Why is there a bump on my butthole?

Studies describe several possible causes of a bump right at the anus, most commonly hemorrhoids (swollen blood vessels), abscesses (infected pus pockets), or skin tags; less often, it's a wart-like growth caused by HPV. Because these can look similar, a doctor needs to examine it to tell them apart.

Why is there a bump at the top of my bum crack?

A bump right at the top of the buttock crease, near the tailbone, is the classic location for a pilonidal cyst — a pit where hair gets trapped under the skin and causes inflammation. Studies found this type of cyst is more common in people with a deeper buttock crease.

Why do I keep getting bumps on my butt?

Bumps that keep recurring in the same spot are often linked to conditions like pilonidal sinus disease or hidradenitis suppurativa (a condition causing recurring boil-like lumps), both described here as tending to come back even after treatment. If bumps keep returning, a doctor can check which of these, or something else, is responsible.

Why do I have bumps on my inner butt cheeks?

The studies in this review describe a wide range of possible buttock lumps, from common cysts and infections to rarer benign tumors, mostly reported as single cases. No study pins down how common each cause is on the inner buttock specifically, so this is an area where seeing a doctor is the only way to know for sure.

When should I see a doctor about a bump near my anus?

See a doctor if the bump is painful, growing, bleeding, discharging pus, or not going away, since case reports describe rare but serious look-alikes such as abscesses that can spread rapidly, or tumors that mimic hemorrhoids. A clinical exam, and sometimes a biopsy, is the only reliable way to tell a harmless bump from something that needs treatment.

Why is there a bump on my butt or anus?

Name: Why is there a bump on my butt or anus?
Published: 2026-10-26
Keywords: why is there a bump on my butthole, why do i have a bump on my butt crack, why is there a bump at the top of my bum crack, why is there a bump on my butt hole, why do i keep getting bumps on my butt, why do i have bumps on my inner butt cheeks, what does it mean if you have a small bump at the top of your butt crack, why is there a bump near my anus

In people who notice a new lump, nodule, or swelling on the buttock, natal cleft, or perianal/anal region, what are the common causes and how can they be distinguished (e.g., pilonidal cyst, external hemorrhoid, perianal abscess, anal skin tag, genital wart, molluscum contagiosum, folliculitis/boil)?

How people search for this, in their own words

“why is there a bump on my butthole”
“why do i have a bump on my butt crack”
“why is there a bump at the top of my bum crack”
“why is there a bump on my butt hole”
“why do i keep getting bumps on my butt”
“why do i have bumps on my inner butt cheeks”
“what does it mean if you have a small bump at the top of your butt crack”
“why is there a bump near my anus”

Evidence review in plain language · compiled 2026-10-26 · checked 2026-10-26 · next 2026-11-26 · automated review, how it works

Bottom line

A bump on the buttock or near the anus can have many different causes — including common conditions like hemorrhoids, pilonidal cysts, and abscesses, as well as much rarer growths and infections described in individual reports — and only an in-person exam can tell which one explains a particular bump.

A few larger studies looked at specific links: people with a pilonidal sinus (a cyst near the tailbone) tend to have a deeper buttock crease than people without one, and a higher body-mass index is linked to a greater risk of perianal abscess. Other studies describe internal and external hemorrhoids and the bacteria found in infected abscess wounds. Each of these studies looked at one condition on its own rather than comparing different causes of a bump, so they cannot say how often any single cause explains a new bump that someone notices.

How well studied

Some evidence

Answered by 2 studies following patients over time, of limited size or quality.

This question asks why something happens, not whether a treatment works, so there is no benefit-or-harm verdict. What can be shown is how well it has been studied.

answer it directly: 50answer it directly
studies found: 108studies found
randomised trials: 3randomised trials
people studied: 187,232people studied
review of trials: 1review of trials
years covered: 2003–2026years covered

What the research shows

Pilonidal cyst or sinus (hair-filled pit near the tailbone)
Case reports and one study comparing people with and without this condition found it linked to a deeper buttock crease, where trapped hair triggers inflammation and a tunnel with recurring swelling and discharge. This is the classic cause of a bump right at the top of the buttock crease.[1,2,3,4,5,6]
Some evidence
External or thrombosed hemorrhoid
Case reports, a small trial, and case series describe hemorrhoids — swollen blood vessels in or around the anus — as a common cause of a painful or painless lump near the anus. In several reports a lump that looked just like a hemorrhoid on examination turned out instead to be something else, including cancer or melanoma, so a hemorrhoid-like lump still needs a doctor's examination rather than being assumed harmless.[1,2,3,4,5,6,7,8,9,10]
Some evidence
Perianal or perirectal abscess (pus pocket)
Several studies describe a painful, swollen bump caused by infection forming a pocket of pus near the anus, often involving common gut bacteria. Higher body weight and diabetes were linked to these abscesses and to slower healing after drainage.[1,2,3,4,5,6,7,8,9,10]
Some evidence
Genital wart (condyloma acuminatum, from HPV)
Multiple case reports describe large, wart-like, cauliflower-shaped growths around the anus caused by HPV, occurring especially in people with HIV, after an organ or bone-marrow transplant, or during pregnancy, when the immune system has less control over the virus.[1,2,3,4,5,6,7,8,9]
Some evidence
Molluscum contagiosum or folliculitis/boil
No study in this review examined molluscum contagiosum as a cause of a buttock or anal bump, and none specifically described an ordinary boil or inflamed hair follicle as the explanation. Related infections after injections were documented, but these are not the same as a classic boil.[1,2]
Not studied
Rare but serious causes (tumors, cancer, unusual infections)
A large number of single-patient case reports found a bump was actually something rarer: a benign or malignant tumor, melanoma, tuberculosis, a fungal or parasitic infection, or a problem tracking down from deeper in the pelvis. These are each uncommon, but together they explain why an unusual, persistent, or fast-growing bump deserves a look rather than an assumption.[1,2,3,4,5,6,7,8,9]
Some evidence

What the studies found

Case reports and case series describe hemorrhoids, pilonidal sinus disease (a hair-pit near the tailbone that can become infected and swell), and perianal abscesses (pus pockets) as documented causes of a bump near the buttock or anus; these case reports cannot say how common each cause is compared with the others or with other possible causes.[1,2,3,4]
Known risk factors have been identified for some causes: higher body weight is linked to perianal abscess risk, and a deeper buttock crease is linked to pilonidal sinus.[1,2]
In children and teenagers with Crohn's disease, skin tags, abscesses, and fistula tunnels near the anus are a recognized and well-documented part of the disease; one study found this in 41 of 276 children newly diagnosed with Crohn's disease.[1,2,3]
A chart review found specific features — tunnels and extra lesions in the armpits versus fistulas and skin tags — that help tell hidradenitis suppurativa apart from Crohn's-related perianal disease.[1]

Important limitations

Nearly all of this evidence comes from single-patient case reports, which describe one person's unusual bump in detail but cannot say how often any particular cause explains a bump in the general population.[1,2,3,4,5,6]
No study here enrolled a broad group of people who noticed a new bump and then worked out, with numbers, which diagnosis each person actually turned out to have.[1,2]
Many case reports describe rare tumors or infections (sarcomas, melanoma, tuberculosis, parasitic cysts) found when an unusual lump happened to be biopsied — this does not show how often such causes occur in someone with a new bump.[1,2,3,4]
The settings studied vary widely — HIV clinics, chemotherapy wards, dialysis units, pediatric IBD clinics — so a cause documented in one of these groups may not apply to a generally healthy adult.[1,2,3,4]

What kind of studies

Case series86 · 80%
Retrospective7 · 6%
Randomised trial3 · 3%
Prospective cohort3 · 3%
Narrative review3 · 3%
Case-control2 · 2%
Laboratory study1 · 1%
Guideline1 · 1%
Systematic review1 · 1%
Registry1 · 1%

The key studies

Wu et al. 2025
The causal relationship between body mass index and perianal abscess: a Mendelian randomization study
Higher body weight raises abscess riskRetrospectiveModerate qualityRelated question
183,710 people2025
Genetically predicted higher BMI was linked to a higher risk of perianal abscess
Who was studied
People of European ancestry included in genetic studies, with perianal abscess cases and controls
What they received
Higher body mass index (genetically predicted)
Compared with
Lower body mass index (genetically predicted)
Main outcome
Risk of developing a perianal abscess
Quality
This is a genetic (Mendelian randomization) analysis using large existing datasets with consistent results across methods, but it studies obesity as a risk factor rather than directly explaining what a bump on the buttock or anus is.
Limitations
The abstract notes that 'multifactorial mechanisms warrant further investigation' and the study relies on genetic instruments rather than directly observed patients with bumps.
Taken word for word from the abstract
- population European-ancestry genome-wide association study (GWAS) data for BMI (n = 359,983) and perianal abscess (1,287 cases/182,423 controls)
- n 1,287 cases/182,423 controls
- intervention Genetically predicted higher BMI
- comparator higher BMI was causally associated with an increased risk of perianal abscess
- primaryOutcome perianal abscess risk
- result Genetically predicted higher BMI was causally associated with an increased risk of perianal abscess (IVW: OR = 1.94, 95%CI: 1.46-2.68, P = 3.8 × 10⁻⁶).
BMC Gastroenterol · PMID 41382010 · Read it on PubMed ↗
Qiao et al. 2025
Analysis of the distribution characteristics of infecting microorganisms in the wound tissue of patients with perianal abscess combined with infection and the influencing factors of wound healing
Bacterial infection causes the abscess bump.Prospective cohortLow qualityRelated question
200 people2 weeks
Most infections involved E. coli, Klebsiella pneumoniae and Staphylococcus aureus; higher BMI, diabetes, other infections, and stool characteristics were linked to poorer wound healing after surgery
Who was studied
Patients with perianal abscess and infection who had surgery to drain it
Main outcome
Types of bacteria/fungi found in the abscess wound and factors linked to poor wound healing after surgery
Quality
Single-hospital study of 200 patients with no control group and only statistical association analysis, so it cannot firmly establish cause for the bump itself, only factors linked to healing after surgery.
Limitations
Single-center study; authors state findings need confirmation in multi-center, larger studies; focuses on post-surgical wound healing rather than why the abscess/bump develops initially.
Taken word for word from the abstract
- population Two hundred patients with perianal abscess combined with infection admitted to our hospital from January 2023 to May 2024 were selected
- primaryOutcome to identify factors affecting wound healing
- result 316 strains of infecting microorganisms were detected in two hundred patients, including 213 Gram-negative bacteria, 80 Gram-positive, and 23 fungal strains, of which the Gram-negative bacteria were dominated by Escherichia coli (E. coli)and Klebsiella pneumoniae(K. pneumoniae), and the Gram-positive bacteria were dominated by Staphylococcus aureus
- result body mass index, diabetes mellitus, concurrent infections and stool traits were independent risk factors influencing the poor quality of wound healing
- n Two hundred patients with perianal abscess combined with infection
- followUp the healing status of wounds in the 2 weeks after surgery
BMC Gastroenterol · PMID 40234777 · Read it on PubMed ↗
Yamanaka-Takaichi et al. 2025
Differentiating clinical characteristics of perianal inflammatory bowel disease from perianal hidradenitis suppurativa
Different bump patterns point to IBD or HS.RetrospectiveLow quality
263 people2025
HS patients more often had higher BMI, smoking, tunnels and comedones, and extra lesions in armpits/groin, while IBD patients more often had fistulas, abscesses, induration, anal tags, ulcers, anal fissures, and extra lesions in the buttocks and perineum
Who was studied
patients with perianal disease, including those with hidradenitis suppurativa, inflammatory bowel disease, or both, seen at a single clinic over 23 years
Main outcome
clinical features that can tell apart perianal hidradenitis suppurativa from perianal Crohn's-type fistulizing disease as causes of perianal bumps or tunnels
Quality
it is a retrospective single-center chart review with no independent confirmation of the machine-learning model, so the findings are descriptive rather than proven causal explanations.
Limitations
retrospective design, single medical center, relies on chart-recorded features, and uses a predictive model built on the same data it was tested on
Taken word for word from the abstract
- n A total of 263 patients were included (98 with HS, 100 with IBD, and 65 with both IBD and HS).
- population patients with perianal disease evaluated at Mayo Clinic from January 1, 1998, through July 31, 2021
- primaryOutcome construct the diagnostic prediction model to distinguish perianal HS from fistulizing perianal IBD
- result Patients with HS had a higher mean body mass index, a higher smoking rate, and more commonly showed cutaneous manifestations of tunnels and comedones, while fistulas, abscesses, induration, anal tags, ulcers, and anal fissures were more common in patients with IBD.
- result patients with IBD often had lesions in the buttocks and perineum, while those with HS had additional lesions in the axillae and groin
Int J Dermatol · PMID 39306801 · Read it on PubMed ↗
López et al. 2018
Comparative Study of Drainage and Antibiotics versus Drainage Only in the Management of Primary Subcutaneous Abscesses
Study about treating abscesses, not their causeRandomised trialModerate qualityRelated question
165 people7 days
no difference in resolution rate, pain, or healing time between the antibiotics group and the placebo group
Who was studied
patients having drainage of a skin abscess, including some on the buttock/anal area
What they received
antibiotics given after the abscess was drained
Compared with
placebo given after the abscess was drained
Main outcome
whether the abscess had resolved by day 7
Quality
it is a randomized trial but the two groups differed in the types of abscesses they had (more perianal abscesses in the placebo group) and it says nothing about why bumps form, only about treating abscesses already diagnosed
Limitations
study mixes abscesses from many body sites (chest, neck, perianal) rather than focusing on buttock or anal bumps, and does not address causes of bumps, only treatment after drainage
Taken word for word from the abstract
- population patients undergoing incision and drainage (I&D) of a subcutaneous abscess
- intervention Patients were randomly assigned either to receive antibiotic agents (group 1)
- comparator or placebo (group 2) after I&D
- primaryOutcome The primary end point was resolution rate of the abscess at the seventh day.
- result Resolution rate was 96% in group 1 and 93% in group 2, with no statistical difference between both (p = 0.28).
- n One hundred sixty-five patients were included for analysis.
Surg Infect (Larchmt) · PMID 29596040 · Read it on PubMed ↗
Schuurman et al. 2011
[Internal and external haemorrhoids]
Bump is likely a haemorrhoid.Case seriesLow quality
3 people2011
The swellings and bumps were due to haemorrhoids — internal haemorrhoids (from the rectal vascular cushions) causing painless bleeding and prolapse, or external haemorrhoids (from perianal veins) causing a painful lump near the anus
Who was studied
Three patients (women aged 27 and 76, and a 31-year-old man) with anal/perianal symptoms
Main outcome
What caused the bump or swelling near the anus
Quality
This is a report of just three individual cases, so it cannot show how common this cause is in general.
Limitations
Only three cases are described, so findings may not generalize to all bumps on the buttock or anus.
Taken word for word from the abstract
- population The first patient is a 27-year-old woman who had been experiencing incidental rectal blood loss without pain during defecation for 3 months. The second patient is a 76-year-old woman who had been bothered by varying degrees of pain from a swelling nearby the anus for 1 year. The third case involves a 31-year-old man who had had continuous severe pain in the anal area for 3 consecutive days.
- n we present 3 cases of patients with different types of haemorrhoidal disease
- primaryOutcome The first patient appeared to have internal hemorrhoids, whereas different forms of external hemorrhoids affected the patients in the other 2 cases.
- result Internal haemorrhoids develop from the intraluminal corpus cavernosum recti; external haemorrhoids from the perianal marginal veins. Patients with internal haemorrhoids present with symptoms that include blood loss and prolaps feeling during defecation. In patients with external haemorrhoids pain is the prominent symptom.
Ned Tijdschr Geneeskd · PMID 21914230 · Read it on PubMed ↗
Daniel 2010
Anorectal pain, bleeding and lumps
Usually haemorrhoids, a blood clot, or fissureNarrative reviewLow quality
size not given2010
The abstract explains that a bump or lump around the anus is usually due to a perianal haematoma, haemorrhoids, or an anal fissure, but can occasionally be a sign of anal or low rectal cancer presenting in a similar way, so careful examination is needed to tell these apart.
Who was studied
patients seeing a general practice doctor with anal pain, a lump near the anus, or rectal bleeding
Main outcome
what is causing a lump or bump in the anal/perianal area
Quality
It is an educational narrative review for doctors rather than an original study, so it does not test or measure anything itself.
Limitations
This is a general discussion article, not a study with its own patient data or measured outcomes.
Taken word for word from the abstract
- population The patient presenting with anal pain, anal lump or rectal bleeding is a common occurrence in the general practice setting
- primaryOutcome This article discusses three common anorectal conditions: perianal haematoma, haemorrhoids and anal fissure, and briefly discusses the less common, but not to be missed conditions: anal carcinoma and low rectal carcinoma.
- result Anal cancer has similar presentation to haemorrhoids and carcinoma of distal rectum can initially present with a haemorrhoid, so the possibility of anorectal cancer should be considered in any patient presenting with haemorrhoids, tenesmus and change in bowel habit.
Aust Fam Physician · PMID 20628675 · Read it on PubMed ↗
Akinci et al. 2009
Natal cleft deeper in patients with pilonidal sinus: implications for choice of surgical procedure
Deeper buttock crease linked to this bumpCase-controlLow quality
101 people2009
people with pilonidal sinus disease had a deeper natal cleft (buttock crease) than those without it
Who was studied
people with and without pilonidal sinus disease (a bump near the buttock crease)
Main outcome
depth of the natal cleft (buttock crease)
Quality
small case-control comparison measuring one anatomical feature, which cannot show whether the deeper cleft causes the bump or merely happens alongside it
Limitations
Small sample size, case-control design cannot establish cause and effect, only one anatomical measure assessed.
Taken word for word from the abstract
- population The study included 50 patients with pilonidal sinus disease and 51 volunteers.
- primaryOutcome The study was planned to evaluate the depth of natal cleft in patients with pilonidal sinus disease and in healthy persons.
- result The mean natal cleft depth was 27.06 mm in the pilonidal sinus group and 21.07 in the nonpilonidal sinus group. The differences between the two groups were statistically significant (P < 0.01) for natal cleft depth.
- n The study included 50 patients with pilonidal sinus disease and 51 volunteers.
Dis Colon Rectum · PMID 19502869 · Read it on PubMed ↗
Keljo et al. 2009
Course and treatment of perianal disease in children newly diagnosed with Crohn's disease
Crohn's disease can cause perianal lumps.RegistryModerate qualityRelated question
276 people24 months
Of 276 children with new Crohn's disease, 41 had perianal lesions; 13 had only skin tags/fissures and 28 had fistulas and/or abscesses, most of which resolved within a year with medical therapy, though 8 became chronic.
Who was studied
children newly diagnosed with Crohn's disease
Main outcome
type and course of perianal lesions (skin tags, fissures, fistulas, abscesses) and their treatment
Quality
It is a multicenter prospective registry with good follow-up, but it only describes children already diagnosed with Crohn's disease, not the general population with a bump.
Limitations
Observational registry data limited to children already diagnosed with Crohn's disease, not people with an isolated bump of unknown cause.
Taken word for word from the abstract
- population children under 16 years of age newly diagnosed with IBD
- n Of the 276 patients identified, 41 had perianal lesions within 30 days of diagnosis.
- primaryOutcome We sought to characterize perianal disease and its treatment in pediatric patients newly diagnosed with Crohn's disease.
- result Thirteen of these had skin tags and fissures only, whereas 28 had fistulas and/or abscesses. The latter lesions resolved by 1 year in 20 patients, and 8 had chronic/recurrent perianal disease persisting for more than 1 year following diagnosis.
Inflamm Bowel Dis · PMID 19023863 · Read it on PubMed ↗

What actually helps, on this site

More about the condition:

All 108 studiesEvery study that answered the question, with its design, size and result.

The other 100 studiesEverything else the search returned, including anything retracted.

Ye et al. 2026
A case report on the management of sepsis complicated by eroded mixed hemorrhoids following breast cancer chemotherapy
Bump was infected, eroded hemorrhoids.Case seriesVery low qualityRelated question
1 people30 days
Her bump was caused by eroded, swollen hemorrhoids that became infected after they were pushed back in; with intensive antibiotics and wound care the swelling and infection fully healed over 30 days.
Who was studied
a 51-year-old woman with breast cancer undergoing chemotherapy who developed severe immune suppression
What they received
conservative treatment with antibiotics, blood support, and local wound care for eroded hemorrhoids
Main outcome
resolution of the perianal mass and infection
Quality
This is a single, highly unusual case in a severely immunosuppressed cancer patient, so it tells us almost nothing about why a bump occurs in a typical person.
Limitations
Single case report in a patient with severe chemotherapy-induced immune suppression and neutropenia, not representative of typical people with a perianal bump; no control group.
Taken word for word from the abstract
- population A 51-year-old female with stage IIIA human epidermal growth factor receptor 2-positive breast cancer developed a high fever (40.1°C) 1 week after her first cycle of neoadjuvant TCHP
- intervention a conservative strategy was implemented. This included broad-spectrum systemic antibiotics (meropenem, vancomycin, amikacin, amphotericin B sequentially), aggressive hematologic support (granulocyte colony-stimulating factor, blood transfusions), and meticulous multimodal local wound care.
- primaryOutcome After 30 days of treatment, the patient became afebrile, and her perianal swelling and inflammation completely resolved.
- result mixed hemorrhoids with erosion and secondary perianal infection
- result The eroded hemorrhoid healed entirely, allowing for a successful transfer to a lower-level hospital for continued supportive care.
- n A 51-year-old female with stage IIIA human epidermal growth factor receptor 2-positive breast cancer
Medicine (Baltimore) · PMID 42798126 · Read it on PubMed ↗
Wang et al. 2026
Giant condyloma acuminatum in a patient with HIV infection: a case report
HPV-related growth from poorly controlled HIVCase seriesVery low quality
1 people3-month follow-up
the bump was a giant condyloma acuminatum (Buschke-Löwenstein tumor), a benign but locally aggressive HPV-related growth linked to poorly controlled HIV
Who was studied
a 24-year-old man with HIV infection and poor adherence to antiretroviral therapy
Main outcome
what caused a perianal bump/mass
Quality
this is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a similar bump
Limitations
only one patient described, from a specialized HIV/immunocompromised context, so findings may not generalize to typical perianal bumps
Taken word for word from the abstract
- population a 24-year-old man with a 7-year history of HIV infection who had suboptimal adherence to antiretroviral therapy (ART)
- primaryOutcome he developed a gradually enlarging perianal mass with intermittent bleeding and purulent discharge
- result The diagnosis of GCA was established by histopathological examination of the perianal lesion
- result Giant condyloma acuminatum (GCA), also known as Buschke-Löwenstein tumor, is a rare tumor-like lesion associated with human papillomavirus (HPV) infection
- result It occurs more frequently in immunocompromised individuals, particularly those with advanced or suboptimally controlled human immunodeficiency virus (HIV) infection.
- n We describe a 24-year-old man
AIDS Res Ther · PMID 42231443 · Read it on PubMed ↗
Su et al. 2026
Invasive streptococcus pneumoniae infection in the hip joint and thigh muscle group of an adult diagnosed by Q-mNGS: a case report
Hip joint infection caused the swelling.Case seriesVery low qualityRelated question
1 people2026
Imaging showed soft tissue infection around the right hip joint with abscess formation, and testing confirmed Streptococcus pneumoniae as the cause
Who was studied
A 38-year-old male with right buttock and thigh swelling, pain, night sweats, and limited mobility
Main outcome
Identifying the cause of right buttock and thigh swelling
Quality
This is a single case report of one person, so it cannot show how common this cause is or apply broadly.
Limitations
Single case report; describes a deep hip joint and muscle infection with diffuse swelling rather than a discrete bump on the buttock or anus.
Taken word for word from the abstract
- population A 38-year-old male presented with right buttock and thigh swelling, pain, night sweats, and limited mobility for 45 days.
- n We report the case of a young adult male
- primaryOutcome Imaging examination indicated soft tissue infection around the right hip joint with abscess formation.
- result Quantitative meta-genomic next-generation sequencing (Q-mNGS) of joint fluid confirmed S. pneumoniae as the pathogen.
J Pak Med Assoc · PMID 42017731 · Read it on PubMed ↗
Zhang et al. 2026
Fractionated electrocoagulation combined with delayed photodynamic therapy for treating giant perianal condyloma acuminatum: A case report
Bump was a genital wart (condyloma).Case seriesVery low qualityRelated question
1 people2026
The mass caused by condyloma acuminatum (genital warts) was completely cleared after treatment
Who was studied
A patient with a giant wart-like mass around the anus (perianal condyloma acuminatum)
What they received
Staged electrocautery followed by delayed photodynamic therapy
Compared with
No comparator (single case report)
Main outcome
Whether the perianal mass cleared completely
Quality
This is a single patient case report, so it cannot show how common this cause is or how it compares to other causes.
Limitations
Only one patient was described, the abstract does not discuss general causes of perianal bumps, and this report focuses on treatment rather than explaining why such bumps occur.
Taken word for word from the abstract
- population a patient with a giant perianal mass
- intervention staged electrocautery followed by delayed photodynamic therapy
- comparator This paper presents a case of a patient with a giant perianal mass successfully treated with an innovative combined approach
- primaryOutcome leading to complete lesion clearance
- result leading to complete lesion clearance
- n a patient with a giant perianal mass
Photodiagnosis Photodyn Ther · PMID 41966506 · Read it on PubMed ↗
Han et al. 2025
[Multicenter, randomized, open-label, and positive-controlled clinical trial of Pien Tze Huang Capsules combined with Compound Pien Tze Huang Hemorrhoid Ointment in postoperative management of mixed hemorrhoids]
Less wound discharge after hemorrhoid surgeryRandomised trialModerate qualityRelated question
240 people7 days
Less wound fluid discharge by day 7 with the Pien Tze Huang treatment, but no significant difference in bleeding, wound healing, pain, or adverse events compared to the other ointment
Who was studied
Patients who had surgery to remove mixed hemorrhoids
What they received
Oral Pien Tze Huang capsules plus Compound Pien Tze Huang hemorrhoid ointment after surgery
Compared with
Mayinglong Shexiang hemorrhoid ointment after surgery
Main outcome
Wound fluid discharge, bleeding, and healing tissue growth scores after surgery
Quality
It was a reasonably sized multicenter randomized trial, but it was open-label (not blinded) and compared two active treatments rather than a placebo, which limits confidence.
Limitations
Open-label design, no placebo group, and this trial studies postoperative wound care after hemorrhoid surgery rather than explaining why a bump or lump appears on the buttock or anus in the first place.
Taken word for word from the abstract
- population A total of 240 patients who underwent Milligan-Morgan hemorrhoidectomy for mixed hemorrhoids were enrolled and randomly assigned to the treatment or control group
- intervention The treatment group additionally received Pien Tze Huang Capsules orally(2 capsules per dose, 3 times per day) and topical application of Compound Pien Tze Huang Hemorrhoid Ointment(2.5 g, twice per day)
- comparator the control group received topical Mayinglong Shexiang Hemorrhoid Ointment(2.5 g, twice per day)
- primaryOutcome Primary efficacy endpoints included wound exudation scores, wound bleeding scores, and wound granulation tissue formation scores
- result the wound exudation scores on postoperative day 7 was significantly lower in the treatment group compared to that in the control group(P<0.05)
- n A total of 240 patients who underwent Milligan-Morgan hemorrhoidectomy for mixed hemorrhoids were enrolled
Zhongguo Zhong Yao Za Zhi · PMID 41508088 · Read it on PubMed ↗
Li et al. 2026
Diagnostic Utility of Molecular Profiling in a Giant Cellular Blue Nevus
Benign pigmented mole-like growthCase seriesVery low quality
1 people2026
The bump was found to be a giant cellular blue nevus, a benign pigmented melanocytic growth, distinguished from melanoma using molecular and imaging studies
Who was studied
a 22-year-old woman with a bluish-gray mass on the buttock present since childhood
Main outcome
what caused the bump and its diagnosis
Quality
This is a single patient case report, so it cannot tell you how common this cause is or what usually happens.
Limitations
Single case report; findings may not generalize to other buttock bumps.
Taken word for word from the abstract
- population a 22-year-old woman with a 6-cm bluish-gray mass on the left medial buttock that had been present since childhood
- primaryOutcome a diagnosis of giant cellular blue nevus was made
- result In the context of the imaging and molecular study results, a diagnosis of giant cellular blue nevus was made.
- n a 22-year-old woman
Am J Dermatopathol · PMID 41283642 · Read it on PubMed ↗
Ferrer-Márquez et al. 2026
Improvement in perianal pathology and quality of life after bariatric surgery: prospective multicentric study with 12-month follow-up
Weight-loss surgery reduced hemorrhoids and skin flare-ups.Prospective cohortLow qualityRelated question
70 people12 months
At 12 months, fewer patients had symptomatic internal and external hemorrhoids, hidradenitis suppurativa flare-ups dropped, and quality of life improved
Who was studied
obese adults who were candidates for weight-loss (bariatric) surgery
What they received
bariatric surgery (restrictive and hypoabsorptive techniques)
Compared with
same patients before surgery, compared to 12 months after
Main outcome
changes in benign anal conditions (hemorrhoids, hidradenitis suppurativa) and quality of life after surgery
Quality
it followed the same patients before and after surgery without a comparison group, used a modest sample of 70 people, and the authors themselves say more patients and longer follow-up are needed.
Limitations
No control group, relatively small number of patients, and the authors state more studies with larger numbers and longer follow-up are needed to confirm findings.
Taken word for word from the abstract
- population Seventy patients who were candidates for bariatric surgery were included.
- intervention patients who underwent bariatric surgery using restrictive and hypoabsorptive techniques
- comparator The second contact took place 12 months after surgery, in which the variables and questionnaires were recorded again.
- primaryOutcome to describe and analyze benign anal pathology in obese patients who were candidates for bariatric surgery, as well as to assess its evolution after 12 months following weight-loss surgery
- result a significant decrease in both the prevalence of symptomatic internal hemorrhoids and external hemorrhoids (p < 0.001) was observed. The mean number of acute hidradenitis suppurativa flare-ups decreased significantly, to 0.22 over the preceding six months (p < 0.001). Quality of life improved significantly, both generally and in relation to perianal pathology.
- n Seventy patients who were candidates for bariatric surgery were included.
- followUp The second contact took place 12 months after surgery
Rev Esp Enferm Dig · PMID 41247359 · Read it on PubMed ↗
Chen et al. 2025
Extrasphincteric anal fistula with gluteal extension: A case report and literature review
Rare fistula tunneling into buttock.Case seriesVery low quality
1 people18 months
The bump was caused by a complex anal fistula with an infected sinus tract extending into the buttock
Who was studied
A 27-year-old woman with 6 months of pain, swelling, and discharge in the buttocks
Main outcome
What caused the bump/swelling in the buttock area
Quality
This is a single patient's case, so it shows one possible cause of a buttock bump but cannot tell you how common this cause is.
Limitations
Findings come from only one patient, so they cannot be generalized to explain most buttock or anal bumps.
Taken word for word from the abstract
- population A 27-year-old female patient presented with pain, swelling, and purulent discharge in the buttocks persisting for 6 months, with a recent exacerbation over the last 2 days.
- n A 27-year-old female patient presented with pain, swelling, and purulent discharge in the buttocks
- primaryOutcome complex anal fistula, infected sinus in the buttock area, constipation, and mild anemia
- result revealing: complex anal fistula, infected sinus in the buttock area, constipation, and mild anemia
Medicine (Baltimore) · PMID 41239594 · Read it on PubMed ↗
Chen et al. 2025
Perianal mass: gout as the etiology (with a case report)
Gout can cause a perianal lump.Case seriesVery low quality
1 people2025
The lump was initially mistaken for an abscess but was actually caused by gout crystals forming a tophus near the anus
Who was studied
A middle-aged man with a lump near the anus
Main outcome
What caused the perianal lump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly.
Limitations
Only one patient; imaging could not clearly identify gout as the cause before surgery.
Taken word for word from the abstract
- population a middle-aged male patient who was misdiagnosed with perianal abscess
- primaryOutcome the subsequent histopathological examination clearly confirmed the diagnosis of perianal tophi
- result the perianal masses can also be caused by gout
- n a middle-aged male patient
Arab J Gastroenterol · PMID 41206254 · Read it on PubMed ↗
Hruby et al. 2026
Histopathologic characterization of Morel-Lavallée lesion: Report of 6 cases and review of the literature
Bump from traumatic fat/fluid pocketCase seriesLow qualityRelated question
10 people2026
These bumps are caused by a traumatic injury that separates skin and fat from the muscle below, creating a fluid or fat-filled pocket that can feel like a lump; they resolved completely after surgical removal
Who was studied
People with Morel-Lavallée lesions (trauma-induced soft tissue injury), mean age 46, affecting thigh, hip/buttock, or lower leg
Main outcome
What causes these bumps and what they look like under the microscope
Quality
This is a small retrospective case series of only 10 patients from one hospital, so it describes what can cause a bump but can't be generalized or prove how common this is.
Limitations
Very small sample size, single institution, retrospective design, and only 40% of lesions were in the hip or buttock area (the rest were thigh or lower leg).
Taken word for word from the abstract
- population Morel-Lavallée lesions (MLLs) are trauma-induced soft tissue injuries that can clinically mimic neoplasms
- population The combined ten patients presented with a mean age of 46 years (range: 13-72 years) with an equal gender distribution
- population These lesions most frequently involved the thigh (5/10, 50 %), hip or buttock (4/10, 40 %), and less commonly the lower leg (1/10, 10 %)
- primaryOutcome Histologically, most cases exhibited fibroconnective tissue with reactive myofibroblasts, fat necrosis, and fibrin deposition (9/10, 90 %), as well as pseudocyst or cystic components (6/10, 60 %)
- result Clinically, the majority of cases (8/10, 80 %) presented as tender, palpable mass-like lesions
- result All ten patients underwent surgical excision with complete resolution and no complications
- n The combined ten patients presented with a mean age of 46 years
Ann Diagn Pathol · PMID 41130167 · Read it on PubMed ↗
Wang et al. 2026
18 F-FDG PET/CT of Sacrococcygeal Pilonidal Sinus Carcinoma
Rare: long-standing pilonidal cyst turned cancerousCase seriesVery low qualityRelated question
1 people2026
A chronic pilonidal sinus turned into an abscess that drained on its own, and imaging plus pathology found it had progressed to a rare cancer (pilonidal sinus carcinoma) forming a mass connected to a cyst between the buttocks
Who was studied
A 69-year-old woman with a long-standing pilonidal sinus (a pit/cyst near the tailbone and buttock crease)
Main outcome
What caused a mass near the tailbone/buttock crease, shown by PET/CT imaging and confirmed by biopsy
Quality
This is a single patient case report, so it cannot show how common this cause is, only that it is possible.
Limitations
Single case report; no comparison group; cannot indicate how common this cause of a buttock bump is.
Taken word for word from the abstract
- population a 69-year-old woman with a chronic pilonidal sinus that progressed to an abscess and drained spontaneously
- primaryOutcome 18 F-FDG PET/CT imaging
- result The retrorectal-precoccyx irregular mass with sinus tract formation and apparent glucose metabolism, connecting with an intergluteal cyst, was confirmed pathologically as pilonidal sinus carcinoma.
- n a 69-year-old woman
Clin Nucl Med · PMID 40553632 · Read it on PubMed ↗
Guo et al. 2025
Rare giant perianal smooth muscle tumor: A case report
Rare benign muscle tumor, not an abscessCase seriesVery low quality
1 people2 years
The bump was a rare benign smooth muscle tumor of the perianal sphincter, initially mistaken for an abscess, measuring about 6.5 × 5.5 × 4 cm, removed surgically with no recurrence after 2 years
Who was studied
A 48-year-old woman with perianal swelling and pain
Main outcome
What caused the perianal bump/swelling
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a similar bump.
Limitations
Only one patient was described, so findings may not generalize; diagnosis required specialized imaging not available in a typical exam.
Taken word for word from the abstract
- population A 48-year-old woman presented with perianal swelling and pain
- n A 48-year-old woman presented with perianal swelling and pain
- primaryOutcome was diagnosed with a perianal smooth muscle tumor
- result the patient was diagnosed with a perianal smooth muscle tumor, with a size of approximately 6.5 × 5.5 × 4 cm. We succeeded in surgically removing the tumor. The patient was followed up for 2 years after the operation, and her anus functioned well without recurrence.
J Int Med Res · PMID 40275791 · Read it on PubMed ↗
Valiyeva et al. 2025
Angioleiomyoma originating from the ano-rectal wall presenting as a perineal mass: a case report
Rare benign muscle tumor near anus.Case seriesVery low quality
1 people2025
The bump was a rare benign tumor called an angioleiomyoma, growing from the wall near the anus/rectum, confirmed after surgical removal and tissue testing
Who was studied
a 50-year-old man with perineal discomfort and a swelling near the anus/rectum
Main outcome
what was causing the perineal bump
Quality
This is a single patient case report, so it cannot show how common this cause is.
Limitations
Single case only, so findings cannot be generalized to explain most buttock or anal bumps.
Taken word for word from the abstract
- n a 50-year-old male patient
- population a 50-year-old male patient complaining of perineal discomfort and a swelling at the level of the left ischio-rectal fossa, moderately painful
- primaryOutcome This solid mass in the left ischio-rectal space was in close relationship with the wall of the ano-rectal junction.
- result After surgical removal and histopathology, the mass resulted an angioleiomyoma, vascular type, desmin positive, a very rare neoplasm.
Int J Colorectal Dis · PMID 39994024 · Read it on PubMed ↗
Hiremath et al. 2025
Concurrent pilonidal sinus of the nape of the neck and sacrococcygeal region
Trapped hair causes buttock sinus lump.Case seriesVery low quality
1 peopleOne year post-surgery
hair gets trapped under the skin and triggers an inflammatory reaction that forms a sinus tract (tunnel) with recurrent swelling and discharge
Who was studied
a man in his mid-30s with a pilonidal sinus at the tailbone area and back of the neck
Main outcome
why a pilonidal sinus/abscess forms in the buttock crease area
Quality
this is a report of just one unusual patient, so it cannot show how common this cause is for people in general
Limitations
single case report describing a rare, unusual presentation (sinus in two body sites at once), so findings may not generalise
Taken word for word from the abstract
- population The patient, in his mid-30s, presented with recurrent swelling and discharging sinuses in both the nape of the neck and the intergluteal region.
- primaryOutcome Hair entrapment beneath the skin triggers a granulomatous reaction, leading to the formation of a sinus tract.
- result Hair entrapment beneath the skin triggers a granulomatous reaction, leading to the formation of a sinus tract.
- n The patient, in his mid-30s, presented with recurrent swelling and discharging sinuses in both the nape of the neck and the intergluteal region.
- followUp One year post-surgery, the patient showed complete healing with no recurrence observed during follow-up.
BMJ Case Rep · PMID 39842887 · Read it on PubMed ↗
Romanova et al. 2024
Adolescent pilonidal disease laser treatment (a-PiLaT): a pilot study
Laser-treated pilonidal bumps sometimes recurCase seriesLow qualityRelated question
17 people24.5 ± 16.8 months
24% had complications and 18% had the bump come back after laser treatment, over an average follow-up of about 2 years
Who was studied
Adolescents aged 10-17 with pilonidal disease (a bump/sinus in the buttock crease)
What they received
Laser treatment for the pilonidal sinus (PiLaT)
Main outcome
Complication and recurrence rates after treatment, and scar appearance
Quality
This is a small, retrospective case series of only 17 patients with no comparison group, so it gives weak evidence.
Limitations
Retrospective, single-center, small number of patients, no control group for comparison
Taken word for word from the abstract
- population We describe our preliminary experience with PiLaT performed in adolescents aged 10-17 years at our tertiary paediatric surgical hospital from 2019 to 2023.
- population Pilonidal disease (PD) is an acquired condition related to hair-induced mechanical forces on the skin surface of the intergluteal cleft, with subsequent abscess formation with or without a concomitant draining sinus (pit).
- intervention pilonidal disease laser treatment (PiLaT) has recently been recognized as a promising treatment option
- primaryOutcome complication rate of 24% (n = 4) and recurrence rate of 18% (n = 3)
- result complication rate of 24% (n = 4) and recurrence rate of 18% (n = 3)
- n A total of 17 consecutive patients (n = 12 female, 71%) underwent a-PiLaT.
- followUp mean follow-up period was 24.5 ± 16.8 months
Tech Coloproctol · PMID 39141158 · Read it on PubMed ↗
Gokkus et al. 2024
Injection, hematoma, abscess, systemic inflammatory response syndrome, stairway to hell: Case report
Bump from injection injury causing hematoma, abscess.Case seriesVery low qualityRelated question
1 people17 months later
the lump was caused by an injection-related artery injury leading to a hematoma that developed into a deep abscess
Who was studied
a 40-year-old man who developed a buttock lump after a gluteal injection
Main outcome
cause of the buttock lump
Quality
this is a single patient case report, so it cannot show how common this cause of a bump is for people in general
Limitations
only one patient is described, and the artery injury is only described as 'possible' and 'suggesting' rather than confirmed
Taken word for word from the abstract
- population A 40-year-old man presented with pain in his buttock, a fever of 40°, and a lump after a dorso-gluteal injection.
- primaryOutcome The patient was diagnosed with systemic inflammatory response syndrome due to a deep abscess related to a hematoma caused by a possible superior gluteal artery branch injury.
- result Continuous bleeding was detected, suggesting iatrogenic superior gluteal artery branch injury at the time of the injection.
- n A 40-year-old man presented with pain in his buttock, a fever of 40°, and a lump after a dorso-gluteal injection.
- followUp a telephone call 17 months later showed that the patient was completely healthy and able to work
Medicine (Baltimore) · PMID 38996111 · Read it on PubMed ↗
Kebapçı et al. 2024
Pelvic floor imaging in women with hemorrhoidal disease: An anatomical feasibility study
Weaker pelvic floor muscles linked to hemorrhoidsCase-controlLow qualityRelated question
size not given2024
women with hemorrhoidal disease had a larger puborectal hiatus, greater distance to the M line, smaller obturator internus muscle area, and more levator ani muscle defects than women without it
Who was studied
women diagnosed with hemorrhoidal disease (HD) between January 2018 and March 2021
Main outcome
pelvic floor muscle and organ structure measurements on MRI (e.g., puborectal distance, muscle area, levator ani defects)
Quality
This is a small, retrospective comparison of medical records without a reported total sample size, so the findings are preliminary and not strong evidence.
Limitations
Retrospective record review, no total sample size stated, and it studies pelvic floor imaging correlations rather than explaining the cause of a visible buttock or anal bump.
Taken word for word from the abstract
- population women diagnosed with HD between January 2018 and March 2021 were analyzed
- primaryOutcome Parameters including pubococcygeal distance, puborectal distance, posterior anorectal angle, obturator internus muscle area, presence of levator ani muscle defect, genital hiatus length, vaginal length, uterocervical angle, cervix-upper vagina angle, and cervix-middle vagina angle were evaluated.
- result Puborectal hiatus distance was higher in the HD group (59.2 ± 8.7 mm vs. 55.5 ± 7.1 mm, p = 0.03).
- result Obturator internus muscle area was found to be lower in the HD group compared to the non-HD group (1721 ± 291.4 mm2 vs. 1897.5 ± 352.5 mm2, p = 0.02).
- result the presence of unilateral levator ani muscle defect was higher in HD patients (p = 0.03).
Surgeon · PMID 38987115 · Read it on PubMed ↗
Sazal et al. 2024
Gold Standard yet Inconspicuous- Our Experience of Conventional Haemorrhoid Surgeries in a Peripheral Free of Cost Hospital of Bangladesh
Describes hemorrhoid surgery outcomes, not bump causesProspective cohortLow qualityRelated question
64 people12 months
Most patients (87.5%) recovered without complications; a few had delayed wound healing, pain, urinary retention, anal sepsis or bleeding after surgery. The study describes haemorrhoids as a 'piles mass' most often at the usual anal canal sites, with later-stage (grade 3-4) disease being common.
Who was studied
Adult patients with haemorrhoidal disease (average age about 39 years) treated at a low-cost hospital in Bangladesh
What they received
Conventional (traditional) surgery to remove haemorrhoids
Main outcome
Complications and recurrence of haemorrhoids after surgery, followed for 12 months
Quality
This is a small, single-hospital study without a comparison group, so it mainly describes surgical outcomes rather than explaining why bumps occur.
Limitations
Small sample of 64 patients, single center, no control group, and the study focuses on surgical treatment outcomes rather than on diagnosing or explaining the cause of a buttock or anal bump.
Taken word for word from the abstract
- population Total 64 adult patients with mean age 38.6 years and male female ratio 1.7:1 were included in this study
- intervention evaluate the outcome of conventional surgeries
- primaryOutcome Clinico-pathological data and outcome in the form of complications and recurrence within follow-up period was studied
- result Complication less recovery was seen in 56(87.5%) cases, where delayed wound healing and pain was reported in 2(3.6%) patient each, followed by 1(1.6%) each reported urinary retention, anal sepsis, primary bleeding and reactionary bleeding
- result Two (2) piles mass was seen most frequent in 36(56.3%) cases and most of the patients i.e. 44(68.8%) had haemorrhoids only on primary sites (3, 7 and 11 o'clock) of anal canal
- n Total 64 adult patients with mean age 38.6 years and male female ratio 1.7:1 were included in this study
Mymensingh Med J · PMID 38944729 · Read it on PubMed ↗
Dsouza et al. 2024
Benign ectopic prostate-a rare differential for a presacral mass
Rare ectopic prostate tissue causing internal massCase seriesVery low qualityRelated question
1 people2024
The mass was a rare benign growth of ectopic (misplaced) prostate tissue located behind the rectum, found after surgical removal and tissue examination
Who was studied
A man in his mid-40s with long-term pain near the anus
Main outcome
What was causing a mass felt near the rectum/anus area
Quality
This is a single patient case report, so it cannot tell us how common this cause is or apply broadly to others with a similar bump.
Limitations
Single case; mass was presacral (deep internal, behind rectum) rather than a visible buttock or perianal skin bump, and diagnosis required surgery and pathology, not something typical for a simple external lump.
Taken word for word from the abstract
- population A man in his mid-40s presented to the colorectal surgery clinic with complaints of chronic perianal pain for over 20 years.
- n A man in his mid-40s presented to the colorectal surgery clinic
- primaryOutcome he was found to have a tender mass in the retro-rectal plane without any evidence of rectal mucosal irregularity
- result On histopathology, there were features of muscular stroma and bilayered glandular epithelium with clear cytoplasm conclusive of a benign ectopic prostate.
BMJ Case Rep · PMID 38649245 · Read it on PubMed ↗
Dutta 2024
Bio-thermal response during laser haemorrhoidoplasty: an exclusive analytical and numerical approach for theoretical investigation
Lab model of laser heat effects, not symptom causeLaboratory studyVery low qualityRelated question
size not given2024
A theoretical/numerical model of tissue heating during laser haemorrhoid treatment was developed, showing tissue temperature falls with higher blood flow and shorter laser pulse times, with model validated to <1% error
Who was studied
People with haemorrhoids (vascular tissue swelling of the anal canal) - described generally, not a specific patient sample
What they received
Laser haemorrhoidoplasty (1064 nm laser treatment) modeled mathematically for its heat effect on tissue
Main outcome
Temperature/thermal response of anal tissue during laser exposure
Quality
This is a purely theoretical mathematical and numerical modeling study with no real patients, so it cannot explain why a bump occurs in a person.
Limitations
Purely analytical/numerical modeling of tissue heating; no patient population, no information on causes of anal bumps, and no clinical outcome data.
Taken word for word from the abstract
- population Haemorrhoidal disease is identified by declension of the inflamed and bleeding of vascular tissues of the anal canal.
- intervention laser haemorrhoidoplasty is an out-patient and less-invasive laparoscopic procedure
- primaryOutcome Impact of variation of blood perfusion term, laser pulse time and optical penetration depth on temperature response of skin tissue is captured.
- result The tissue temperature decreases along with time of laser exposure with increasing the blood perfusion rate as it carries away large amount of heat.
- result The research outcome is successfully validated with less than 1% of error observed between the appointed analytical and numerical scheme.
Lasers Med Sci · PMID 38647731 · Read it on PubMed ↗
Li et al. 2023
A case report of Mycobacterium fortuitum infection after muscle injection
Infected injection site abscess.Case seriesVery low quality
1 people2 months
The buttock bump was an abscess caused by infection with a rapidly growing mycobacterium (Mycobacterium fortuitum) introduced after an intramuscular injection
Who was studied
51-year-old woman with a lump on her right buttock after intramuscular injections
Main outcome
Cause of the buttock lump/abscess
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to other people with buttock bumps.
Limitations
Single case report; findings may not generalize to other causes of buttock bumps.
Taken word for word from the abstract
- population A 51-year-old female patient was admitted to the hospital due to a lump on her right buttock that emerged after receiving intramuscular injections to treat left shoulder joint pain.
- primaryOutcome Laboratory results from the drainage indicated that the infection was caused by a rapidly growing mycobacteria and was confirmed as Mycobacterium fortuitum by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.
- result Laboratory results from the drainage indicated that the infection was caused by a rapidly growing mycobacteria and was confirmed as Mycobacterium fortuitum by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.
- n A 51-year-old female patient was admitted to the hospital due to a lump on her right buttock
- followUp the patient was discharged after 2 months of treatment
Medicine (Baltimore) · PMID 38050215 · Read it on PubMed ↗
Liang et al. 2023
Application of platelet-rich-plasma in the postoperative treatment of perianal abscess pseudohealing: A case report
Unhealed abscess causing lump.Case seriesVery low quality
1 people2023
The bump was due to a perianal abscess that did not heal properly after surgery, leaving a fistula under the skin
Who was studied
A patient with perianal swelling, pain, and a bump near the anus caused by a perianal abscess, after surgery
Main outcome
Why there was a persistent bump/swelling near the anus
Quality
This is a single patient case report, which cannot show how common this cause is or rule out other causes.
Limitations
Only one patient; no comparison group; findings may not generalize.
Taken word for word from the abstract
- population The patient had reported a complaint of perianal swelling and discomfort associated with anal pain, which was considered a perianal abscess.
- n The patient had reported a complaint of perianal swelling
- result the wound remained unhealed for more than 3 months, and there was a fistula under the skin
- primaryOutcome Perianal color ultrasonography revealed perianal abscess.
Medicine (Baltimore) · PMID 37986293 · Read it on PubMed ↗
Yigit et al. 2022
A rare cause of acute anal pain: strangulated hemorrhoids in a perianal fistula
Hemorrhoid trapped in fistula tractCase seriesVery low quality
size not given2022
The bump was a strangulated hemorrhoid caught in a perianal fistula tract, a rare mechanical cause of painful swelling near the anus
Who was studied
A person with hemorrhoidal disease and an anal fistula causing painful swelling
Main outcome
What is causing the painful anal/buttock bump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly.
Limitations
Single case report; no numbers given for how common this cause of anal bumps is.
Taken word for word from the abstract
- population Hemorrhoidal disease is characterized by painless rectal bleeding and palpable swelling in the anus and very common in the society.
- primaryOutcome This case report shows that strangulated hemorrhoidal disease can also develop due to a mechanical cause as a result of incarceration of the hemorrhoid into the accompanying perianal fistula tract.
- result strangulated hemorrhoidal disease can also develop due to a mechanical cause as a result of incarceration of the hemorrhoid into the accompanying perianal fistula tract.
Ann Ital Chir · PMID 37070227 · Read it on PubMed ↗
Zhongguo Zhong Yao Za Zhi 2022
[Expert consensus on clinical application of Fufang Jingjie for Fumigation and Washing]
Does not explain cause of bump.GuidelineVery low qualityRelated question
size not given2022
This is an expert consensus statement about a traditional Chinese medicine wash (Fufang Jingjie), not a study explaining why a bump on the buttock or anus occurs; it lists conditions treated (external/mixed/internal hemorrhoids, anal fissures, perianal abscess, anal fistula, perianal eczema) but does not explain causes of bumps.
Who was studied
People with anal/perianal diseases causing bumps or swelling
Quality
This is a consensus/expert opinion document about a treatment, not research evidence about why a bump occurs.
Limitations
It is a treatment-focused consensus statement, not a study addressing causes or diagnosis of anal/buttock bumps.
Taken word for word from the abstract
- population It is widely used for the treatment of external hemorrhoids, mixed hemorrhoids, internal hemorrhoids prolapse and incarceration, anal fissures, perianal abscess, anal fistula acute attack, perianal eczema and other diseases.
- result this consensus invites front-line clinical experts from anorectal department to compile, referring to the relevant clinical literature and guide, combining with the clinical treatment experience of experts, the function, usage, dosage, adverse reactions and points for attention were discussed of Fufang Jingjie for Fumigation and Washing.
Zhongguo Zhong Yao Za Zhi · PMID 36472015 · Read it on PubMed ↗
Allisha et al. 2022
Secondary healing of horseshoe perianal abscess in a patient with morbid obesity: experience at a rural hospital
Bump was a perianal abscessCase seriesVery low quality
1 people8 weeks
The swelling was a horseshoe-shaped perianal abscess (pus collection) that had spread around both sides of the anus into the surrounding tissue, linked to his severe obesity
Who was studied
A man with severe obesity who had painful swelling around his anus
Main outcome
Why a bump or swelling formed around the anus
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to other people with a bump near the anus.
Limitations
Single case report from one hospital; findings cannot be generalized.
Taken word for word from the abstract
- population A 35-year-old male with morbid obesity presented to the surgery outpatient clinic in a hospital in Subang, West Java, Indonesia, with continuous severe pain and swelling around the anus of approximately 7 days' duration.
- primaryOutcome Local examination of the anogenital area revealed a horseshoe perianal abscess extending to the ischiorectal fossa
- result Local examination of the anogenital area revealed a horseshoe perianal abscess extending to the ischiorectal fossa, approximately 1 cm from the anal verge and measuring 7.5 cm × 4.5 cm × 10 cm.
- n A 35-year-old male with morbid obesity presented
Wounds · PMID 36108243 · Read it on PubMed ↗
Omorodion et al. 2021
Solitary asymptomatic lobular perianal nodule on an infant
Benign hair-follicle growth (FSCH).Case seriesVery low quality
1 people2021
the bump was a benign growth made of hair follicles and sebaceous (oil) glands, called folliculosebaceous cystic hamartoma
Who was studied
an infant boy with a bump near the anus, first noticed at 6 months of age
Main outcome
what kind of growth the perianal bump was
Quality
this is a single infant case report, so it cannot show how common this cause is or rule out other causes.
Limitations
only one patient was described, and the abstract does not explain how common this cause is compared to other causes of perianal bumps
Taken word for word from the abstract
- population We present an infant boy exhibiting a tumor with overlap features between an FSCH and fibrofolliculoma in the perianal region that was first noticed at 6 months of age.
- n We present an infant boy
- primaryOutcome The histological examination showed a hamartomatous benign proliferation of hair follicles and disordered sebaceous glands
- result which is consistent with the infundibular structures and radiating sebaceous glands that are typically observed in previously reported cases of FSCH
Dermatol Online J · PMID 35130389 · Read it on PubMed ↗
Gkegkes et al. 2021
Sweetening … the pain: The role of sugar in acutely prolapsed haemorrhoids
Swollen prolapsed hemorrhoids cause the bump.Narrative reviewLow quality
size not given2021
The abstract explains that an anal/buttock bump can be caused by acutely prolapsed internal hemorrhoids, which swell, become inflamed and cause pain, and can be treated by applying sugar to reduce the swelling so the tissue retracts back into the anal canal.
Who was studied
people with acute prolapse of internal hemorrhoids
Main outcome
explanation of why a bump appears at the anus
Quality
This is a descriptive/narrative piece about a clinical technique with no study design, patient numbers, or data reported.
Limitations
No numbers, methodology, or outcome data are given; it reads as a narrative description rather than a study.
Taken word for word from the abstract
- population Acute prolapse of internal haemorrhoids is presented with oedema, inflammation and acute pain.
- result The application of granulated sugar on swollen hae-morrhoids leads to an immediate reduction of their edema and to the patient's relief.
- result After the topical application of sugar, haemorrhoids begin to shrink immediately and edema is drastically reduced, while haemorrhoidal tissue can easily retracted back into the anal canal.
- primaryOutcome Haemorrhoids are considered among the most frequent proctologi-cal condition at a general practitioner (GP) practice.
Clin Ter · PMID 34821343 · Read it on PubMed ↗
Shamloul et al. 2021
Recurrent fungating tumor and a chronic rash in an immunosuppressed transgender patient: a case of Buschke-Lowenstein condyloma and epidermodysplasia verruciformis
HPV-related wart tumor from immune suppressionCase seriesVery low quality
1 people2021
A large wart-like tumor (Buschke-Löwenstein condyloma) grew from the anus onto the buttocks, linked to HPV infection in a person with suppressed immunity
Who was studied
A transgender woman in her 40s with HIV and prior testicular cancer treated with radiation, who was immunosuppressed
Main outcome
What caused a growing anal/buttock tumor
Quality
This is a single patient's case, so it cannot show how common this cause is in general.
Limitations
Single case report; findings may not generalize; exact HPV subtype causing the tumor was not clearly identified.
Taken word for word from the abstract
- population A transgender female in her 40s with history of HIV and testicular cancer status post-genital X-irradiation presented with a perianal mass and pruritic rash across her chest.
- primaryOutcome Physical examination revealed a bulky, verrucous tumor protruding outward from the anus involving the medial buttocks.
- result Clinically and histologically the lesions were consistent with Buschke-Löwenstein condyloma (BLC) and acquired epidermodysplasia verruciformis (AEDV).
- result This case demonstrates a possible role of beta HPV or rarer HPV subtypes in the pathogenesis of verrucous carcinoma, particularly in the setting of immunosuppression.
- n A transgender female in her 40s
Dermatol Online J · PMID 34755967 · Read it on PubMed ↗
Costa Almeida et al. 2021
Buschke-Löwenstein tumour: a rare and challenging entity
Rare wart-like tumour, can turn cancerous.Case seriesVery low qualityRelated question
1 people2021
Counted as a related question: This study focuses on Buschke-Löwenstein tumour, a specific rare malignant tumor, rather than addressing the general question of what causes a bump on the buttock or anus—which could be benign conditions like hemorrhoids, cysts, lipomas, or other common causes.
The bump was diagnosed as a Buschke-Löwenstein tumour, a rare, locally aggressive wart-like growth of the anal/perianal area that can turn cancerous
Who was studied
a 57-year-old man with a large wart-like growth around the anus
Main outcome
what causes a cauliflower-like bump around the anus
Quality
This is a single patient case report, so it cannot show how common this cause is or how it compares to other causes of an anal bump.
Limitations
Only one patient is described, limiting how much can be generalised about causes of anal bumps in general.
Taken word for word from the abstract
- population A 57-year-old male patient resorted to surgical consultation with a giant perianal cauliflower-like mass.
- n A 57-year-old male patient resorted to surgical consultation with a giant perianal cauliflower-like mass.
- primaryOutcome The common presentation is an anal mass with a cauliflower-like appearance.
- result A BLT was diagnosed.
- result Buschke-Löwenstein tumour (BLT) is rare and locally aggressive, and malignant transformation is a possibility.
BMJ Case Rep · PMID 34531235 · Read it on PubMed ↗
Deh et al. 2020
[Cutaneous tuberculosis affecting the buttock in an immunocompetent adult patient]
Buttock lump was skin tuberculosis.Case seriesVery low quality
1 peoplesix months
The bump was caused by skin tuberculosis (cutaneous tuberculosis) linked to active lung tuberculosis, showing as a hardened plaque with nodules and pus discharge, confirmed by tissue examination showing granulomas and detection of TB bacteria; it healed after six months of TB treatment
Who was studied
A 47-year-old immunocompetent man with a painful swelling on his buttock for four years
Main outcome
Cause of a buttock lump/swelling
Quality
This is a single patient case report, so it cannot tell us how common this cause is or apply broadly.
Limitations
Single case report from a TB-endemic area; findings may not generalize to other populations or causes of buttock bumps.
Taken word for word from the abstract
- population a 47-year-old man admitted for a painful swelling in the right gluteal region that had evolved for four years
- n This study involved a 47-year-old man
- primaryOutcome The diagnosis of skin tuberculosis was retained based on histological examination
- result Physical examination objectified a polyfistulized hardened plaque characterized by confluent nodules and discharge of yellowish pus in the lower and inner face of the right buttock associated with bilateral inguinal inflammatory adenopathies.
- result The diagnosis of skin tuberculosis was retained based on histological examination which showed tuberculoid granuloma and the detection of Alcohol-Acid Resistant Bacilli (BAAR) in the gastric fluid.
- result The patient achieved recovery after six months of tuberculosis treatment.
Pan Afr Med J · PMID 33796203 · Read it on PubMed ↗
Ma et al. 2021
Rare case of granular cell tumor of perianal region: a case report and literature review
Rare benign tumor (granular cell tumor).Case seriesVery low quality
1 people2021
the lump was a rare benign tumor called a granular cell tumor, confirmed after surgical removal and biopsy
Who was studied
a 36-year-old woman with a lump near the anus
Main outcome
what was causing the perianal lump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others.
Limitations
Single case report; findings may not generalize to other people with similar bumps.
Taken word for word from the abstract
- population a 36-year-old woman with a perianal lump with no obvious local lesion as the main clinical complaint
- n a 36-year-old woman
- primaryOutcome perianal lump with no obvious local lesion as the main clinical complaint
- result The tumor was completely resected and histologically confirmed as a GCT.
J Int Med Res · PMID 33459105 · Read it on PubMed ↗
Muggli 2020
[Onset and management of perianal vein thrombosis]
Painful clot under anal skinNarrative reviewLow quality
size not given2020
Sudden anal pain with a painful perianal swelling indicates perianal vein thrombosis, which can be diagnosed by appearance alone and, if within 72 hours of onset, successfully removed surgically
Who was studied
People with a sudden painful swelling near the anus
Main outcome
What causes the bump and how it is diagnosed and treated
Quality
This is a narrative description of a condition without a study design, sample, or data to weigh.
Limitations
No methodology, data, or patient numbers are given; it is a general clinical description rather than a study.
Taken word for word from the abstract
- population Acute onset of anal pain is a classic symptom of perianal vein thrombosis.
- primaryOutcome the diagnosis can be made without further diagnostic measures and the targeted therapy can be initiated
- result An acute perianal vein thrombosis can be successfully excised within the first 72 hours.
Ther Umsch · PMID 32870098 · Read it on PubMed ↗
Abdalla et al. 2020
Ischio-anal fossa hydatid cyst
Rare parasite cyst caused the bump.Case seriesVery low quality
1 people1-year follow-up
the bump was a hydatid cyst (a parasitic infection) located in the ischio-anal fossa near the anus
Who was studied
a 46-year-old woman with a painless lump near the anus for 8 months
Main outcome
cause of a perianal mass or lump
Quality
This is a single patient case report, so it cannot show how common this cause is, only that it can happen.
Limitations
Only one patient was described, so the finding may not generalize to other people with similar bumps.
Taken word for word from the abstract
- n a 46-year-old female who had complained of painless left perianal mass for 8 months
- population a 46-year-old female who had complained of painless left perianal mass for 8 months
- primaryOutcome surgical and pathological examination revealed the diagnosis of hydatid disease of ischio-anal fossa
- result surgical and pathological examination revealed the diagnosis of hydatid disease of ischio-anal fossa
- result Hydatid disease of the perianal area, although rare, must be kept in the differential diagnosis of pathologies of any perianal mass or lump.
Int J Infect Dis · PMID 31981765 · Read it on PubMed ↗
Amarnani et al. 2020
Aneurysmal benign fibrous histiocytoma of the anal canal: a rare differential diagnosis
Rare benign tumor causing anal bump.Case seriesVery low quality
1 people2020
the bump was a rare benign tumor called aneurysmal benign fibrous histiocytoma, found in the anal canal, which was surgically removed with no symptoms left afterward
Who was studied
a 48-year-old man with a painful anus, bleeding, and feeling of needing to pass stool
Main outcome
what was causing the anal mass and lump
Quality
this is a single patient case report, so it cannot tell us how common this cause of a bump is or what usually happens.
Limitations
only one patient described, so findings may not generalize; no comparison group.
Taken word for word from the abstract
- population a 48-year-old Caucasian male presenting with a 2-week history of a painful anus, fresh rectal bleeding and tenesmus
- n a 48-year-old Caucasian male
- primaryOutcome Digital rectal examination identified a tender firm mass in the anal verge.
- result Biopsies taken of the mass confirmed the diagnosis of an aneurysmal benign fibrous histiocytoma (BFH).
- result The patient made a full recovery and had no residual symptoms.
Int J Colorectal Dis · PMID 31845025 · Read it on PubMed ↗
Wheelwright et al. 2019
Perianal Histoplasmosis Presenting as a Mass Suspicious for Malignancy: A Case Report with Review of Gastrointestinal Manifestations of Histoplasmosis
Rare fungal infection mimicking cancer.Case seriesVery low quality
1 people5-months follow-up
A painful, hard bump near the anus that looked like cancer on imaging turned out to be a fungal infection (histoplasmosis), not cancer, confirmed by biopsy and blood tests; it improved with antifungal treatment.
Who was studied
66-year-old man with a painful bump near the anus
Main outcome
what caused the perianal mass/bump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a similar bump.
Limitations
Single case; findings may not generalize to most people with a perianal or buttock bump, who are far more likely to have common causes like abscess, hemorrhoid, or cyst rather than a rare fungal infection.
Taken word for word from the abstract
- population a 66-year-old male patient who presented with an indurated painful perianal lesion that appeared highly suspicious for malignancy on imaging
- primaryOutcome A biopsy of the mass was performed
- result showing chronic inflammation with clusters of epithelioid histiocytes containing characteristic, PAS-fungus stain-positive, intracellular yeast forms consistent with histoplasmosis. There was no evidence of malignancy.
- n a 66-year-old male patient
- followUp at 5-months follow-up, the patient reported significant improvement in signs and symptoms
Am J Case Rep · PMID 31761896 · Read it on PubMed ↗
Kobayashi et al. 2019
Mixed Actinomyces israelii and Aggregatibacter actinomycetemcomitans infection causing empyema necessitatis and multiple skin abscesses in an immunocompetent patient
Rare infection caused buttock abscess.Case seriesVery low qualityRelated question
1 people2019
A mixed bacterial infection (Actinomyces israelii and Aggregatibacter actinomycetemcomitans) caused abscesses in multiple body sites including the left buttock, along with a chest wall infection
Who was studied
A 45-year-old man with chest pain and multiple abscesses, including one on the buttock
Main outcome
Cause of abscesses found on buttock and elsewhere
Quality
This is a single patient case report, which cannot show how common this cause is or apply to most people with a buttock bump.
Limitations
Single case report of a rare infection in one person; cannot be generalized to typical buttock bumps.
Taken word for word from the abstract
- population A 45-year-old- man presented with left chest wall pain, swelling and cough.
- n A 45-year-old- man presented with left chest wall pain, swelling and cough.
- primaryOutcome Over a 2-month period he developed abscesses in the right foot, right anterior thigh, left buttock and left chest.
- result Actinomyces israelii was recovered in culture with extended incubation.
- result the culture initially grew Aggregatibacter actinomycetemcomitans and Eikenella corrodens
BMJ Case Rep · PMID 31551318 · Read it on PubMed ↗
Cui et al. 2019
Giant condyloma acuminatum in pregnancy: A case report
Bump was a large genital wart (HPV).Case seriesVery low quality
1 people2019
the bump was diagnosed as a giant condyloma acuminatum (an HPV-related genital wart) that was surgically removed after delivery
Who was studied
pregnant woman with large growths around the anus and perineum
Main outcome
identifying what caused the bump and how it was treated
Quality
this is a single patient case report with no comparison group, so it cannot show how common this cause is.
Limitations
only one patient was described, and findings from a single case may not apply broadly.
Taken word for word from the abstract
- population we presented a GCA case in a pregnant woman with giant masses that covered the perineal and perianal region
- n we presented a GCA case in a pregnant woman
- primaryOutcome In this report, we presented a GCA case in a pregnant woman with giant masses that covered the perineal and perianal region.
- result The giant condyloma acuminatum (GCA), also known as Buschke-Löwenstein tumor (BLT), is a type of human papilloma virus-associated sexually transmitted infection.
- result we decided to resect the tumor 2 weeks after the infant was delivered via C-section
Dermatol Ther · PMID 31141268 · Read it on PubMed ↗
Huang et al. 2019
Characteristics of chondroid lipoma: A case report and literature review
Benign fatty tumor (chondroid lipoma)Case seriesVery low quality
1 people6 months
the bump was diagnosed as chondroid lipoma, a rare benign fatty tumor, confirmed by pathology after the tumor was surgically removed
Who was studied
a person with a lump on the left buttock
Main outcome
what the bump on the buttock turned out to be
Quality
this is a single patient case report, so it cannot show how common this cause of a buttock bump is or how it compares to other causes
Limitations
only one patient was studied, so findings may not generalize, and there is no comparison group
Taken word for word from the abstract
- n we report a case of CL with a mass on the left buttock for 2 weeks
- population a mass on the left buttock for 2 weeks
- primaryOutcome The diagnosis of CL was rendered according to the pathological indices.
- result Chondroid lipoma (CL) is a rare benign tumor.
- result The tumor was resected completely under spinal anesthesia.
Medicine (Baltimore) · PMID 31083243 · Read it on PubMed ↗
Hsieh et al. 2019
Epidemiology and outcomes of anal abscess in patients on chronic dialysis: a 14-year retrospective study
Abscess found as a cause in dialysis patientsRetrospectiveLow qualityRelated question
43 peopleone-year
Perianal abscess was the most common type of anal abscess, and 39.5% of patients experienced fistula formation. Most patients had mixed aerobic and anaerobic flora.
Who was studied
chronic dialysis patients who were hospitalized for a first-time anal abscess
Main outcome
the type of anal abscess, whether a fistula formed, and the bacteria found, along with hospital survival and recurrence
Quality
This is a small retrospective chart review of only 43 dialysis patients from one hospital, so it mainly describes abscesses in that narrow group rather than explaining bumps in people generally.
Limitations
retrospective chart review limited to chronic dialysis patients at a single center over 14 years, with no comparison to non-dialysis patients
Taken word for word from the abstract
- population 43 chronic dialysis patients with first-time anal abscess were enrolled
- primaryOutcome The endpoints of this study were in-hospital mortality, one-year mortality and one-year recurrence.
- result Perianal abscess was the most common type of anal abscess, and 39.5% of patients experienced fistula formation. Most patients had mixed aerobic and anaerobic flora.
- n 43 chronic dialysis patients with first-time anal abscess were enrolled
Clinics (Sao Paulo) · PMID 30916172 · Read it on PubMed ↗
Liao et al. 2019
Idea and innovation: Secure fixation between dermis and periosteum using perforator flap to prevent recurrence of pilonidal sinus disease
Bump caused by pilonidal sinus disease.Case seriesVery low qualityRelated question
1 people3 years
the bump was caused by recurrent pilonidal sinus disease — a condition with sinus tracts, abscess, and infection in the gluteal region — which was treated with surgical removal and flap reconstruction
Who was studied
an 18-year-old woman with a recurring pilonidal sinus (a type of cyst/abscess) near the buttock crease
Main outcome
what caused the swelling and infection in the buttock area, and how it was surgically treated
Quality
this is a single patient case report describing one surgical technique, so it cannot establish general causes of buttock bumps.
Limitations
single case only; focuses on a surgical repair technique rather than explaining why bumps occur in general; not generalisable to other causes of buttock or anal bumps
Taken word for word from the abstract
- population An 18-year-old female with recurrent pilonidal sinus disease over right medial gluteal region presented with sacral pain and infection.
- primaryOutcome She developed progressive swelling and burst of abscess from several sinus tracts and did not respond to the treatment with antibiotics alone.
- result After radical excision of the entire pilonidal sinus and adjacent fibrotic tissue, a deep and large defect was measured.
- n An 18-year-old female with recurrent pilonidal sinus disease
Int Wound J · PMID 30240147 · Read it on PubMed ↗
Shi et al. 2018
Endometriosis in the rectum accompanied by hemorrhoids leading to diagnostic pitfalls: a rare case report
Rare internal rectal endometriosis mimicking hemorrhoids.Case seriesVery low qualityRelated question
1 people2018
a small endometriosis mass was found in the wall of the rectum, located deep inside (8 cm from the anus), which could be mistaken for other conditions because it occurred together with hemorrhoids
Who was studied
a patient with hemorrhoids accompanied by endometriosis in the rectum
Main outcome
finding the cause of a rectal mass found alongside hemorrhoids
Quality
this is a single patient case report, so it cannot show how common this cause of a bump is or rule out other causes.
Limitations
single case report; the mass was located deep in the rectum rather than visibly on the buttock or anus, and findings from one patient may not generalize.
Taken word for word from the abstract
- population a rare case of a patient with hemorrhoids accompanied by endometriosis in the rectum
- primaryOutcome its diagnosis may be difficult, especially when it is combined with other diseases
- result The mass was approximately 0.8 cm × 0.6 cm and located in the muscularis and submucosa of the rectum 8 cm from the anus.
- n we present a rare case of a patient with hemorrhoids accompanied by endometriosis in the rectum
BMC Womens Health · PMID 29973210 · Read it on PubMed ↗
Chen et al. 2018
Successful treatment following early recognition of a case of Fournier's scrotal gangrene after a perianal abscess debridement: a case report
Abscess bump turned into rare severe infection.Case seriesVery low qualityRelated question
1 peopledischarged on the 11th postoperative day
The bump was found to be a perianal abscess, and the patient went on to develop Fournier's gangrene (a severe infection) after abscess debridement
Who was studied
A 29-year-old man who had surgery for a perianal abscess
Main outcome
What caused severe perianal and scrotal swelling and pain after abscess surgery
Quality
This is a single patient's case, so it cannot show how common this is or what usually causes a bump in this area.
Limitations
Single case report; focuses on a rare and severe complication (Fournier's gangrene) rather than on typical causes of a perianal or buttock bump.
Taken word for word from the abstract
- n A 29-year-old Asian man
- population A 29-year-old Asian man who had undergone surgical debridement at another hospital to treat a perianal abscess 5 days earlier
- primaryOutcome A diagnosis of Fournier's gangrene was made.
- result A physical examination revealed a perianal abscess. Furthermore, the scrotum was gangrenous and exhibited extensive cellulitis in the perineum and bilateral inguinal area.
J Med Case Rep · PMID 29945675 · Read it on PubMed ↗
Calleja et al. 2019
Mutational analysis of high-grade spindle cell sarcoma of the femur in Mazabraud's syndrome
Rare genetic muscle tumor (Mazabraud's syndrome).Case seriesVery low qualityRelated question
1 people2019
Imaging and biopsy showed the buttock mass was a soft-tissue myxoma (a benign tumor) in the adductor muscle region, occurring together with a rare bone disorder (fibrous dysplasia) and a bone cancer in the same leg, all linked to the same genetic mutation — a condition called Mazabraud's syndrome
Who was studied
a 36-year-old woman with knee pain and a buttock mass
Main outcome
what was causing the buttock mass
Quality
This is a single rare case report, so it cannot tell you how likely this cause is for a typical buttock bump.
Limitations
Single case report of an extremely rare syndrome combining fibrous dysplasia, soft-tissue myxoma, and sarcoma; not representative of common causes of buttock or anal bumps.
Taken word for word from the abstract
- population a 36-year-old woman with right anterior knee pain and a buttock mass
- primaryOutcome a mass with myxoid signal characteristics in the right adductor region
- result Biopsy of the adductor mass confirmed a soft-tissue myxoma
- result Molecular genetic analysis revealed an identical R201H substitution in the GNAS1 gene in the sarcoma, the myxoma, and also the conventional fibrous dysplasia.
- n a 36-year-old woman
Skeletal Radiol · PMID 29804209 · Read it on PubMed ↗
Deckers et al. 2017
Perineal aggressive angiomyxoma in a menopausal woman
Rare tumour reaching into buttock.Case seriesVery low qualityRelated question
1 people2017
The bump was found to be a rare benign but locally invasive tumour (aggressive angiomyxoma) originating from the vaginal wall and extending into the buttock and underlying tissue
Who was studied
A 58-year-old menopausal woman first diagnosed with a Bartholin's cyst
Main outcome
What was causing the mass/bump in the perineal and buttock area
Quality
This is a single case report, so it cannot show how common this cause is or apply broadly to people with buttock bumps.
Limitations
Only one patient described; the mass originated from the vaginal wall rather than being a primary buttock or anal lesion, and no information is given about typical presentation in the general population.
Taken word for word from the abstract
- population We describe the case of a 58-year-old woman, initially treated for a Bartholin's cyst.
- primaryOutcome Histological examination indicated the presence of an AA.
- result The MRI showed a 7 cm soft tissue mass extending from the lateral wall of the vagina, into the left buttock and down into the subcutaneous tissue.
- n 58-year-old woman
BMJ Case Rep · PMID 29222207 · Read it on PubMed ↗
Granese et al. 2018
Vulvar involvement in pediatric Crohn's disease: a systematic review
Perianal skin tags, nodules seen in Crohn'sSystematic reviewLow qualityRelated question
22 people2018
Perianal and/or anal involvement (fissures, vegetations, skin tags, erythema, papules, nodules) were recorded in ten cases (45.4%)
Who was studied
children and teens diagnosed with vulvar Crohn's disease
Main outcome
what bumps, swelling, sores or skin changes show up on the vulva and around the anus in pediatric Crohn's disease
Quality
it only pools 22 published case reports of a rare pediatric condition, with no comparison group and no general population included.
Limitations
Based on collected case reports rather than a systematic study of unselected patients with buttock or anal bumps; focused specifically on children with known Crohn's disease, not people in general presenting with a bump.
Taken word for word from the abstract
- population Twenty pediatric studies and 22 cases of VCD were included for analysis.
- n Twenty pediatric studies and 22 cases of VCD were included for analysis.
- primaryOutcome Clinical vulvar examination showed the following main manifestations
- result Perianal and/or anal involvement (fissures, vegetations, skin tags, erythema, papules, nodules) were recorded in ten cases (45.4%).
Arch Gynecol Obstet · PMID 28948431 · Read it on PubMed ↗
Toyoki et al. 2017
A Giant Dermatophyte Abscess Caused by Trichophyton rubrum in an Immunocompromised Patient
Fungal infection mimicking a cyst.Case seriesVery low quality
1 people2017
the bump was a large fungal (dermatophyte) abscess caused by Trichophyton rubrum, which looked just like a common sebaceous cyst (atheroma)
Who was studied
a 73-year-old man who had been on immunosuppressive drugs for 15 years
Main outcome
cause of a growing lump on the buttock
Quality
this is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a buttock bump
Limitations
only one patient described, and he was immunocompromised for 15 years, which may not reflect typical cases
Taken word for word from the abstract
- population A 73-year-old male who had been receiving immunosuppressive drugs for 15 years developed a nodule on the left buttock region.
- n A 73-year-old male
- primaryOutcome The nodule slowly grew into a 15-cm fluctuant multilocular subcutaneous cyst.
- result the yellow purulent fluid obtained from the cyst was positive for Trichophyton rubrum
- result Notably, the clinical manifestations closely resembled those of a huge atheroma.
Med Mycol J · PMID 28566660 · Read it on PubMed ↗
Chen et al. 2017
Clinicopathological features and differential diagnosis of aggressive angiomyxoma of the female pelvis: 5 case reports and literature review
Rare tumor can cause buttock lumpCase seriesVery low qualityRelated question
5 people42 months
The masses were diagnosed as aggressive angiomyxoma, a rare tumor of the pelvis and perineum; one case occurred in the buttock, and two of the five patients had the tumor come back after surgery
Who was studied
women with slow-growing masses in the pelvis, vulva, or buttock (mean age 42)
Main outcome
identifying the cause of the mass through imaging and pathology
Quality
Only 5 cases were studied, with just one buttock case, so it says little about how common this cause is in general.
Limitations
Very small number of cases, mostly pelvic or vulvar rather than buttock, and the paper is a case series rather than a study designed to determine causes of buttock bumps generally.
Taken word for word from the abstract
- n we present five cases of AAM with mean age of 42
- population The patients mainly presented slow-growing mass in the abdomen and perineum (3 cases in the pelvis, 1 in the vulva, and 1 in the buttock)
- primaryOutcome Through the pathological examination, its positivity to estrogen and progesterone receptors can justify enlargement and recurrence, confirming the tumor is AAM
- result Two patients recurred 8 and 15 months after surgery, respectively.
- result Aggressive angiomyxoma (AAM) is a rare mesenchymal tumor that usually occurs in the pelvis and perineum of young females.
- followUp The longest follow-up was 42 months.
Medicine (Baltimore) · PMID 28514296 · Read it on PubMed ↗
Rashidi et al. 2017
Unexpected Presentation of Perianal Granular Cell Tumor in a Young Woman
Rare benign tumor caused the bumpCase seriesVery low quality
1 people2017
The bump was a rare benign tumor called a granular cell tumor, found after surgical removal
Who was studied
a previously healthy 36-year-old woman with a lump near the anus
Main outcome
what caused the perianal bump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others.
Limitations
Only one patient described; findings cannot be generalized.
Taken word for word from the abstract
- population a previously healthy 36-year-old woman who presents with a slow growing, painless lump in her perianal region
- primaryOutcome was found to have a granular cell tumor on microscopic evaluation
- result underwent surgical excision and was found to have a granular cell tumor on microscopic evaluation
- n a previously healthy 36-year-old woman
Curr Probl Diagn Radiol · PMID 28284459 · Read it on PubMed ↗
Cevolani et al. 2017
Elastofibroma of the gluteal region with a concomitant contralateral lesion: case report and review of the literature
Benign fibrous tumor in buttock muscle.Case seriesVery low quality
1 people2017
the mass was found to be an elastofibroma, a benign soft-tissue tumor located between the gluteal muscles
Who was studied
a 51-year-old man with a slow-growing mass in the buttock
Main outcome
identifying what the buttock mass was
Quality
this is a single patient case report, so it cannot show how common this cause is or rule out other explanations.
Limitations
only one patient described; no comparison group; findings may not generalize to other causes of buttock bumps.
Taken word for word from the abstract
- population A 51-year-old man presented with elastofibroma (EF) of the gluteal region with a concomitant contralateral lesion.
- population The patient presented with a slow growing mass of the proximal third of the right buttock and had swelling, discomfort in sitting, and right-hip pain during walking for 2 months.
- primaryOutcome It was pathologically confirmed to be an EF.
- result It was pathologically confirmed to be an EF.
- result At surgery, a soft, non-encapsulated, irregular, and rubber-like mass was found attached to the gluteus medius muscles.
- n A 51-year-old man presented with elastofibroma (EF) of the gluteal region with a concomitant contralateral lesion.
Skeletal Radiol · PMID 28058477 · Read it on PubMed ↗
Cordova et al. 2016
Recurrent Pediatric Perianal Swelling
Can signal Crohn's disease in kidsCase seriesVery low qualityRelated question
size not given2016
In children with Crohn's disease, perianal swelling can be caused by skin tags, abscesses, fistulas (abnormal tunnels), or narrowing of the rectum as part of the disease
Who was studied
Children with inflammatory bowel disease, especially Crohn's disease, who have recurring swelling near the anus
Main outcome
What causes recurrent swelling or bumps around the anus in children
Quality
This is a case report and review article without original study data or a comparison group, so it only describes possible causes rather than testing them.
Limitations
Abstract describes a specific pediatric IBD population and does not address other common causes of perianal or buttock bumps in the general population.
Taken word for word from the abstract
- population Pediatric inflammatory bowel disease is a chronic gastrointestinal disease consisting of Crohn's disease (CD) and ulcerative colitis (UC).
- primaryOutcome Perianal skin tags, perianal abscesses, recto-cutaneous fistulae, and rectal stenosis are among the phenotypic characteristics of perianal CD.
- result Perianal skin tags, perianal abscesses, recto-cutaneous fistulae, and rectal stenosis are among the phenotypic characteristics of perianal CD.
Pediatr Ann · PMID 26878185 · Read it on PubMed ↗
Dulskas et al. 2015
Giant gluteal lipoma presenting as a sciatic hernia
Fatty tumor causing a hidden pelvic herniaCase seriesVery low quality
1 people1 year
The bump was a large fatty tumor (lipoma) that had pushed through a sciatic hernia opening in the pelvis, displacing the rectum and bladder
Who was studied
A 53-year-old man with a painful bump on his buttock
Main outcome
What caused the gluteal bump
Quality
This is a single patient case report, so it cannot show how common this cause is for people with a buttock bump.
Limitations
Single case report; findings may not generalize to other causes of gluteal or anal bumps.
Taken word for word from the abstract
- population A 53-year-old male presented with an expanding, slightly reducible, right gluteal painful mass
- primaryOutcome We report a case of gluteal lipoma protruding into pelvis, displacing rectum with bladder and presenting as a sciatic hernia.
- result Computer tomography (CT scan) demonstrated a large intra- and extra-pelvic fatty mass traversing the greater sciatic foramen. The tumor was surgically removed through lower middle laparotomy approach. Subsequent pathological examination revealed lipoma.
- n A 53-year-old male presented
Hernia · PMID 26668862 · Read it on PubMed ↗
Kurt et al. 2016
Massive localized lymphedema: a clinicopathologic study of 46 patients with an enrichment for multiplicity
Rare obesity-linked swelling, almost never perianal.RetrospectiveLow qualityRelated question
46 people2016
Masses occurred mostly on the thigh (33 cases) and abdomen (17), with only one case in the perianal region out of 54 total cases; the condition was linked to severe obesity, cardiovascular disease, and diabetes, and some patients had multiple masses
Who was studied
middle-aged, morbidly obese adults (most Caucasian) who developed large body masses over months to years
Main outcome
clinical and pathological features of massive localized lymphedema (a benign tumor-like swelling)
Quality
This is a retrospective review of archived cases from one hospital, so it describes patterns but cannot prove why the condition happens, and it only touches on the buttock/anal area in a single case.
Limitations
Retrospective single-center chart review; perianal involvement was seen in only 1 of 54 lesions, so findings mostly describe thigh/abdomen masses rather than buttock or anal bumps specifically.
Taken word for word from the abstract
- n Forty-six patients (21 males and 25 females, mean age 50 years) presented with large masses developing over a 5-60-month period.
- population Massive localized lymphedema is a monstrous tumefactive pseudosarcoma seen in middle-aged morbidly obese adults.
- primaryOutcome we report the largest study of massive localized lymphedema and expand upon its clinicopathologic features
- result The sites included thigh (n=33), abdomen (n=17), suprapubic region (n=1), mons pubis (n=6), scrotum (n=2), perianal region (n=1), and right flank (n=1).
- result We suggest that obesity itself and the related metabolic syndrome have an important role in its pathogenesis.
Mod Pathol · PMID 26585553 · Read it on PubMed ↗
Gopal et al. 2015
Primary Anal Canal Syphilis in Men: The Clinicopathologic Spectrum of an Easily Overlooked Diagnosis
Anal bump or ulcer can be syphilisCase seriesLow quality
4 people2015
Three patients had anal canal ulcers and one had an ulcerated anal mass; syphilis was often missed clinically and only diagnosed through biopsy showing characteristic plasma cell-rich inflammation, confirmed with Treponema pallidum staining.
Who was studied
Men with anal canal lesions, some HIV-positive, who were found to have primary syphilis
Main outcome
How primary syphilis in the anal canal presents clinically and under the microscope
Quality
This is a small descriptive series of only 4 patients with no comparison group, so it can only suggest a pattern, not prove how common this is.
Limitations
Only 4 cases reviewed at what appears to be a single center, with no systematic follow-up or population-based data on frequency.
Taken word for word from the abstract
- n To describe 4 cases of primary syphilis presenting in the anal canal
- population All 4 patients were male, of whom 2 were HIV positive.
- primaryOutcome To describe 4 cases of primary syphilis presenting in the anal canal to increase awareness of its presentation and morphology in this location, as the diagnosis can be easily overlooked clinically and by the pathologist.
- result Three patients presented with anal canal ulcers; one presented with an ulcerated anal mass.
Arch Pathol Lab Med · PMID 26317454 · Read it on PubMed ↗
Guttadauro et al. 2015
Circumferential anal giant condyloma acuminatum: a new surgical approach
Rare HPV-caused anal wart growth.Case seriesLow qualityRelated question
3 people1-year follow-up
The abstract describes perianal giant condyloma acuminatum as a circumferential, exophytic, cauliflower-like mass with an irregular warty surface, located in the anal region and related to human papillomavirus infection
Who was studied
People with a rare wart-like growth around the anus caused by HPV infection
Main outcome
What causes this type of growth around the anus
Quality
Only three patients were described in a technical report about a surgery, not a study designed to explain why these bumps occur in general.
Limitations
Very small number of cases (3), focused on a specific rare HPV-related condition and a surgical technique rather than on the broader question of anal/buttock bumps in general.
Taken word for word from the abstract
- population Perianal giant condyloma acuminatum is a rare clinical condition related to human papillomavirus infection
- result characterized by a circumferential, exophytic, cauliflower-like mass with an irregular warty surface localized in the anal region
- n no recurrence of condylomatosis in any of the 3 cases
- primaryOutcome Perianal giant condyloma acuminatum is a rare clinical condition related to human papillomavirus infection and characterized by a circumferential, exophytic, cauliflower-like mass with an irregular warty surface localized in the anal region.
Dis Colon Rectum · PMID 25751807 · Read it on PubMed ↗
Hyun et al. 2015
Giant anal condyloma (giant condyloma acuminatum of anus) after allogeneic bone marrow transplantation associated with human papillomavirus: a case report
Large wart from HPV infectionCase seriesVery low quality
1 people2015
A large cauliflower-like anal bump was a giant condyloma (wart) caused by HPV, occurring due to a weakened immune system after bone marrow transplant
Who was studied
A 31-year-old man with leukemia after bone marrow transplant, with a perianal mass
Main outcome
Cause and nature of the anal/buttock bump
Quality
This is a single patient case report, so it cannot show how common this cause is or apply to most people with a bump.
Limitations
Single case, immunocompromised patient after transplant, not generalizable to general population causes of buttock/anal bumps.
Taken word for word from the abstract
- population A 31-year-old Korean man presented to our hospital with anal discomfort for more than one month due to a protruding mass.
- n A 31-year-old Korean man presented to our hospital
- result Gross findings revealed a large perianal cauliflower-like mass over 7cm in size with invasion of the anal orifice. He was diagnosed with giant anal condyloma occurring after an allogeneic bone marrow transplantation.
- primaryOutcome He was diagnosed with giant anal condyloma occurring after an allogeneic bone marrow transplantation.
J Med Case Rep · PMID 25597932 · Read it on PubMed ↗
Kong et al. 2014
Recurrent painful perianal subcutaneous angiomatoid fibrous histiocytoma: a case report and review of the literature
Rare recurring tumor, mistaken for a cystCase seriesVery low quality
1 people2014
The bump was a rare soft-tissue tumor called angiomatoid fibrous histiocytoma, initially mistaken for a sebaceous cyst, which kept coming back and needed three surgeries to treat
Who was studied
A patient with a recurring painful lump near the anus
Main outcome
What caused the perianal bump
Quality
This is a single patient case report, so it cannot tell us how common this cause is or what usually happens.
Limitations
Single case report; findings may not generalize to other people with a similar bump.
Taken word for word from the abstract
- population we present a case of recurrent subcutaneous perianal AFH
- n After an initial diagnosis as a sebaceous cyst
- primaryOutcome we were able to use immunohistochemical findings to correctly identify the mass as an AFH
- result After an initial diagnosis as a sebaceous cyst, we were able to use immunohistochemical findings to correctly identify the mass as an AFH. The patient was effectively treated after 3 surgical resections.
Medicine (Baltimore) · PMID 25526437 · Read it on PubMed ↗
Chavada et al. 2014
Uncommon manifestations of Listeria monocytogenes infection
Rare bacterial infection caused an abscess.Case seriesVery low quality
3 people2014
The perianal abscess was found to be caused by infection with the bacterium Listeria monocytogenes, identified only after microbiological culture of the abscess specimen
Who was studied
A 60 year old Asian man with a perianal abscess (one of three unrelated case reports of unusual Listeria infections)
Main outcome
What caused the bump/abscess near the anus
Quality
This is a single case report within a small case series, so it shows one possible cause but cannot say how common it is.
Limitations
Only one case of perianal abscess is described; diagnosis was delayed and based on a single patient, so this cannot be generalised to most people with a similar bump.
Taken word for word from the abstract
- population 3) A 60 year old Asian man with perianal abscess
- n We present 3 cases of Listeria monocytogenes presenting as focal infections
- primaryOutcome Listeria was not thought to be causative organism in any of these cases until microbiological specimens isolated the organism.
- result All of these patients had Listeria monocytogenes isolated from clinical specimens.
- result 3) A 60 year old Asian man with perianal abscess
BMC Infect Dis · PMID 25466213 · Read it on PubMed ↗
Lim et al. 2015
Comparing topical hydrocortisone cream with Hai's Perianal Support in managing symptomatic hemorrhoids in pregnancy: a preliminary trial
Hemorrhoids in pregnancy, not a different bumpRandomised trialLow qualityRelated question
23 people2015
Both treatments improved symptoms, but the perianal support device showed significantly greater improvement in pain, swelling and discomfort compared to the cream
Who was studied
pregnant women past 28 weeks with symptomatic hemorrhoids
What they received
Hai's Perianal Support toilet seat device
Compared with
topical hydrocortisone cream 1%
Main outcome
improvement in hemorrhoid symptoms: pain, swelling, bleeding, itching, discomfort
Quality
Very small trial of only 23 women described as preliminary, so the results are not reliable enough to draw firm conclusions.
Limitations
Small sample size; study authors themselves state more trials are needed to reconfirm findings.
Taken word for word from the abstract
- population 23 pregnant women with gestation above the 28th week and presented with symptomatic hemorrhoids
- intervention a HPS, a posterior perineal support toilet seat device (Colorec)
- comparator topical hydrocortisone cream 1%
- primaryOutcome data on symptoms of pain, itching, swelling, discomfort and bleeding associated with hemorrhoids
- result statistically significant differences were found on symptoms of pain, swelling and discomfort between the test and control groups
- n 23 pregnant women
J Obstet Gynaecol Res · PMID 25256125 · Read it on PubMed ↗
Dohan et al. 2014
Diffusion-weighted MR imaging for the diagnosis of abscess complicating fistula-in-ano: preliminary experience
Anal fistula can cause abscess bumpRetrospectiveLow qualityRelated question
24 people2014
The diffusion MRI technique detected abscesses and fistula tracks with high accuracy, distinguishing an abscess from simple inflamed tissue
Who was studied
patients with a known fistula-in-ano (a tunnel-like infection near the anus)
Main outcome
how well a special MRI scan (diffusion-weighted imaging) could spot an abscess complicating an anal fistula
Quality
This is a small retrospective study of 24 patients from one center, described by the authors themselves as preliminary experience, so it cannot reliably explain for a general reader why a bump appears.
Limitations
Small sample size (24 patients), retrospective design, single-center, authors call it preliminary experience; it addresses imaging technique for a known fistula-in-ano, not the general question of why a bump appears on the buttock or anus.
Taken word for word from the abstract
- population 24 patients with a fistula-in-ano
- primaryOutcome To investigate the role of diffusion-weighted magnetic resonance imaging (DWMRI) in the diagnosis of abscess-complicating fistula-in-ano
- result DWMRI shows high sensitivity and specificity for the diagnosis of perianal abscesses and helps discriminate between an abscess and inflammatory mass.
- n MRI examinations, including fat-suppressed T2-weighted turbo spin-echo (T2-TSE) MRI and DWMRI, of 24 patients with a fistula-in-ano, were reviewed
Eur Radiol · PMID 25038854 · Read it on PubMed ↗
Tariq et al. 2014
Aggressive angiomyxoma: swirled configuration on ultrasound and MR imaging
Rare soft-tissue tumour, not common cause.Case seriesVery low qualityRelated question
1 people2014
The mass was found to be an aggressive angiomyxoma, a rare slow-growing tumour that can present as a soft tissue mass in the vulva, perianal area, buttock or pelvis
Who was studied
a 40-year-old woman with a pelvic/perineal mass
Main outcome
what type of tumour was causing the mass and its imaging appearance
Quality
This is a single case report, so it cannot show how common this cause is or how it compares to other causes of a buttock bump.
Limitations
Single patient case report; the mass was pelvi-perineal, not confined to the buttock or anus specifically, and the condition is described as rare in young women.
Taken word for word from the abstract
- population a 40 years old woman with a left pelvi- perineal mass since 5 years
- primaryOutcome Histapathology after excision gave a diagnosis of Aggressive Angiomyxoma
- result Aggressive angiomyxoma is often clinically misdiagnosed because of its variable presentation as a soft tissue mass of the vulva, perianal region, buttock or pelvis
- n a 40 years old woman
J Pak Med Assoc · PMID 24864615 · Read it on PubMed ↗
Kim et al. 2014
Intra-abdominal low-grade fibromyxoid sarcoma of the transverse mesocolon mimicking lymphoma
Rare abdominal tumor, not a buttock lump caseCase seriesVery low qualityRelated question
1 people2014
The mass was a rare soft tissue cancer called low-grade fibromyxoid sarcoma, arising from the transverse mesocolon, with specific imaging appearances on ultrasound, CT and MRI; this tumor type can also occur in the buttock region
Who was studied
A young female patient with a tumor in the abdomen (transverse mesocolon)
Main outcome
What the intra-abdominal mass was and how it appeared on imaging
Quality
This is a single case report about a rare abdominal tumor, not a study of buttock or anal bumps, so it offers almost no evidence for this question.
Limitations
Single case report; the tumor described was intra-abdominal, not a buttock or anal bump; only mentions buttock as one of several sites where this tumor type can occur in general.
Taken word for word from the abstract
- population We report the first case of LGFMS arising from the transverse mesocolon mimicking lymphoma in a young female patient.
- primaryOutcome radiologic findings of LGFMS showed a well-demarcated multilobular hypoechoic mass on ultrasonography, a multilobular homogeneously enhancing solid mass in the transverse mesocolon on computed tomography and a mildly inhomogeneously enhancing solid mass with two different components on magnetic resonance imaging
- result LGFMS commonly involves the deep soft tissues of the lower extremities, inguinal area, shoulder, axilla, neck and buttock.
- n Intra-abdominal LGFMS has been reported in ten cases in six English studies
Jpn J Radiol · PMID 24652000 · Read it on PubMed ↗
Kerkeni et al. 2014
Lipoblastoma in childhood: about 10 cases
Rare fatty tumor can cause buttock lumpCase seriesVery low qualityRelated question
10 people42 months (ranges between 18 and 84 months)
In this group of 10 children with lipoblastoma, the tumour could occur in several places including mediastinum, thigh, buttock, groin/scrotum, abdomen, and back; complete surgical removal was done and no lumps came back after a median of 42 months.
Who was studied
children with a rare benign fatty tumour (lipoblastoma), ages 7 months to 9 years
Main outcome
what causes a soft-tissue lump and how it was treated
Quality
This is a small retrospective case series of only 10 children with lipoblastoma in many different body locations, not focused on buttock lumps, so it cannot tell how often this is the cause of a buttock or anal bump.
Limitations
Very small sample (10 cases) spanning many anatomical sites; only one case was located in the buttock, and none were anal; no comparison group; retrospective design.
Taken word for word from the abstract
- population There were six boys and four girls ranging in age from 7 months to 9 years.
- primaryOutcome A soft-tissue mass was the main complain in nine patients.
- result The various locations of the mass were mediastinal, thigh, buttock, inguino-scrotal, the greater omentum and the Latissimus dorsi.
- result complete excision was done. The median time of follow-up was 42 months (ranges between 18 and 84 months). There were no recurrences.
- n A total of 10 cases of pathologically proven lipoblastoma from 2003 to 2012 were reviewed.
- followUp The median time of follow-up was 42 months (ranges between 18 and 84 months).
Afr J Paediatr Surg · PMID 24647290 · Read it on PubMed ↗
Subramaniam et al. 2013
The development of Fournier's gangrene following rubber band ligation of haemorrhoids
Rare severe infection after hemorrhoid banding.Case seriesVery low qualityRelated question
1 people2013
The swelling was due to Fournier's gangrene (necrotising fasciitis) that developed as a rare complication of the banding procedure, requiring extensive surgery
Who was studied
An 80-year-old man with diabetes who had recently had a hemorrhoid banding procedure
Main outcome
Cause of perianal pain and swelling after hemorrhoid banding
Quality
This is a single patient case report, which cannot show how common or typical this cause of swelling is.
Limitations
Single case report in a high-risk patient (elderly, diabetic) after a specific medical procedure, not a general population presenting with an unexplained bump.
Taken word for word from the abstract
- population an 80-year-old male patient with diabetes after a routine outpatient haemorrhoid banding procedure
- n an 80-year-old male patient
- primaryOutcome the patient noticed an increasing amount of pain and swelling of the perianal region
- result Histology studies later confirmed the presence of necrotising fasciitis
- result The development of Fournier's gangrene in an 80-year-old male patient with diabetes after a routine outpatient haemorrhoid banding procedure is described
BMJ Case Rep · PMID 24287481 · Read it on PubMed ↗
Yamashita et al. 2013
Intramuscular myxoma of the buttock mimicking low-grade fibromyxoid sarcoma: diagnostic usefulness of MUC4 expression
Benign fatty lump, not cancer.Case seriesVery low qualityRelated question
1 people3 years
Counted as a related question: This study examines how to distinguish between two specific rare benign and malignant tumors (intramuscular myxoma vs. low-grade fibromyxoid sarcoma) in a single case, rather than addressing the common reasons a person develops a bump on their buttock or anus.
The mass was found to be a benign intramuscular myxoma, not the malignant tumor it was first thought to be, and there was no recurrence after 3 years
Who was studied
a person with a lump in the buttock region
Main outcome
figuring out whether the buttock mass was a benign tumor or a low-grade malignant tumor
Quality
This is a single case report, so it cannot show how common this cause of a buttock bump is.
Limitations
Only one patient was described, and diagnosis required specialized imaging and lab testing not available to typical patients.
Taken word for word from the abstract
- population We describe a case of IM of the buttock region mimicking low-grade fibromyxoid sarcoma.
- primaryOutcome absence of MUC4 expression is the definitive key to distinguish IM from LGFMS
- result therefore, a conclusive diagnosis of IM was made
- result The patient had no local recurrence at the 3-year follow-up.
- n We describe a case of IM of the buttock region
Skeletal Radiol · PMID 23685711 · Read it on PubMed ↗
Rajah et al. 2014
Unusual manifestations of a common gastrointestinal disorder
Crohn's disease caused an anal fistula.Case seriesVery low qualityRelated question
1 people18 months after diagnosis of CD he developed perianal disease
He developed perianal disease with a fistula and distal anal stricture 18 months after his Crohn's disease diagnosis, which was treated with a seton and escalation of therapy
Who was studied
A 13-year-old boy later found to have Crohn's disease
Main outcome
Cause of perianal swelling/bump (fistula and anal stricture)
Quality
This is a single patient case report, so it cannot show how common this cause of an anal bump is in general.
Limitations
Single case report in a child with an unusual, multi-system presentation of Crohn's disease; not generalisable to typical anal or buttock bumps.
Taken word for word from the abstract
- population a 13-year old male who presented with bilateral scrotal redness, swelling and tenderness
- primaryOutcome he developed perianal disease with a fistula and distal anal stricture
- result Eighteen months after the diagnosis of CD he developed perianal disease with a fistula and distal anal stricture. He was successfully treated with insertion of a seton and escalation of therapy to azathioprine and infliximab.
- n a 13-year old male
J Paediatr Child Health · PMID 23662656 · Read it on PubMed ↗
Alliez et al. 2013
[The persistent sciatic artery aneurysm. A rare and painful buttock mass]
Rare artery aneurysm causing the lump.Case seriesVery low quality
1 people2013
Surgery found the mass was an aneurysm (a bulging, weakened area) of a rare leftover blood vessel from before birth called the persistent sciatic artery, pressing on nearby nerves
Who was studied
A 56-year-old man with a painful buttock mass and leg nerve symptoms for 3 years
Main outcome
What was causing the painful buttock mass
Quality
This is a single patient case report, so it cannot show how common this cause is or apply to most people with a buttock bump.
Limitations
Only one patient; no information on how common this cause is in the general population.
Taken word for word from the abstract
- population A 56-year-old man presents a right painful buttock mass with L5-S1 radicular symptoms for 3 years.
- primaryOutcome a rare cause of painful buttock mass with L5-S1 radicular signs
- result The surgical exploration found a pulsatile vascular mass like a persistent sciatic artery aneurysm.
- n A 56-year-old man presents a right painful buttock mass
Ann Chir Plast Esthet · PMID 23582620 · Read it on PubMed ↗
Johnson et al. 2013
Case report: misdiagnosis of tailgut cyst presenting as recurrent perianal fistula with pelvic abscess
Rare hidden cyst behind rectum mimicking fistulaCase seriesVery low quality
1 people2013
The lump was a tailgut cyst, a rare presacral mass, which had been misdiagnosed as recurrent perianal fistula and abscess until surgery and pathology identified it
Who was studied
A 16-year-old girl with pelvic pain and repeated perianal fistula and abscess problems
Main outcome
What was causing her recurrent perianal fistula and abscess
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a bump near the anus.
Limitations
Only one patient; diagnosis made after multiple prior unnecessary procedures; no information on how often this cause occurs.
Taken word for word from the abstract
- population a 16-year-old female who presented with pelvic pain
- primaryOutcome recurrent perianal fistula and perirectal abscess
- result was surgically removed using a combined transanal and posterior sagittal excision technique and was found to be a tailgut cyst upon pathologic evaluation
- n a 16-year-old female
J Pediatr Surg · PMID 23414899 · Read it on PubMed ↗
Maitra et al. 2012
Obstructive perianal lesion in a 75-year-old man
Prolapsed haemorrhoids mimicking cancerCase seriesVery low quality
1 people1 month post-admission to discharge, then until elective haemorrhoidectomy
The fungating perianal mass turned out to be prolapsed haemorrhoids, not cancer; it shrank with sugar and charcoal dressings and later became a small skin tag after haemorrhoidectomy
Who was studied
a 75-year-old man with a perianal mass
Main outcome
what was causing the perianal lump that looked malignant
Quality
This is a single patient case report, so it cannot show how common this cause is in general.
Limitations
Only one patient; findings cannot be generalised to explain all perianal bumps.
Taken word for word from the abstract
- population A 75-year-old man presented with a fungating peri-anal mass
- primaryOutcome A provisional diagnosis of prolapsed haemorrhoids was made
- result There was a dramatic resolution of the mass with this treatment and the patient was discharged 1 month post-admission
- result by which time the mass had decreased to a perianal skin tag
- n A 75-year-old man presented with a fungating peri-anal mass
BMJ Case Rep · PMID 22802557 · Read it on PubMed ↗
Uth Ovesen 2012
[Perianal Buschke-Löwenstein tumour]
Giant wart-like growth, sometimes cancerous.Case seriesVery low quality
1 people2012
The bump was a giant cauliflower-like growth called a Buschke-Löwenstein tumour, and tissue testing showed it was a verrucous carcinoma, a type of slow-growing cancer that doesn't spread to other parts of the body but can invade nearby tissue
Who was studied
a 49-year-old man with a large bump near the anus
Main outcome
what the perianal bump turned out to be on examination
Quality
This is a single patient case report, so it cannot tell us how common this cause of a bump is or how it usually behaves.
Limitations
Single case report; no information on how typical this presentation is or how it compares to other causes of perianal bumps.
Taken word for word from the abstract
- population We report a case of a 49-year-old male patient with a 17 × 10 cm large perianal Buschke-Löwenstein tumour
- primaryOutcome where histologic findings showed the presence of verrucous carcinoma
- result We report a case of a 49-year-old male patient with a 17 × 10 cm large perianal Buschke-Löwenstein tumour where histologic findings showed the presence of verrucous carcinoma.
- n We report a case of a 49-year-old male patient
Ugeskr Laeger · PMID 22673386 · Read it on PubMed ↗
Mavrogianni et al. 2012
Therapeutic combination of radiofrequency surgical dissection and oral acitretin in the management of perianal Buschke-Lowenstein tumour: a case report
HPV-caused giant anal wartCase seriesVery low quality
1 people26 months
the bump was a giant condyloma acuminatum (Buschke-Löwenstein tumour), a rare, large wart-like growth around the anus caused by HPV types 6 and 11, known for invading locally and often coming back after treatment
Who was studied
young man with a large bump near the anus (perianal mass), causing pain during bowel movements
Main outcome
what causes this kind of bump and what it is
Quality
this is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a similar bump
Limitations
only one patient, so findings may not generalize; no comparison group
Taken word for word from the abstract
- population a young man with anogenital GCA, presenting with a large perianal mass and pain during defaecation
- primaryOutcome Giant condyloma acuminatum (GCA), or Buschke-Löwenstein tumour (BLT), is a rare large tumour of the anogenital area.
- result It is caused by human papillomavirus genotypes 6 and 11, and it is characterized by aggressive local invasion and frequent recurrences after treatment.
- n We report a case of a young man with anogenital GCA
Int J STD AIDS · PMID 22648893 · Read it on PubMed ↗
Menon et al. 2012
Low-grade fibromyxoid sarcoma, a deceptively benign tumor in a 5-year-old child
Rare cancer causing buttock lumpCase seriesVery low quality
1 people2012
the bump was a rare type of soft tissue cancer called low-grade fibromyxoid sarcoma, which looks harmless but can spread; surgery was the treatment used
Who was studied
a 5-year-old boy with a lump in his buttock
Main outcome
what the bump was and how it was treated
Quality
this is a single case report, so it cannot show how common this cause is or how it compares to other causes of buttock bumps
Limitations
only one patient described; no way to know how often this explains a buttock bump in general
Taken word for word from the abstract
- n We report a case of a 5-year-old boy who presented with a mass in the left buttock.
- population We report a case of a 5-year-old boy who presented with a mass in the left buttock.
- result Although benign in appearance, these lesions can behave aggressively, with local recurrence and distant metastases primarily to lungs.
- result surgical resection being the treatment of choice
- primaryOutcome We report a case of a 5-year-old boy who presented with a mass in the left buttock.
Pediatr Surg Int · PMID 22130782 · Read it on PubMed ↗
Leung et al. 2011
Tumoral calcinosis: a case report
Buttock bump was benign calcium deposit (tumoral calcinosis).Case seriesVery low qualityRelated question
1 people4-year follow-up
the buttock lump, like the elbow lump, was diagnosed as tumoral calcinosis (a benign calcium deposit) with no sign of cancer
Who was studied
an 11-year-old girl with a calcified lump on her elbow and buttock
Main outcome
what was causing the lumps on the buttock and elbow
Quality
this is a single patient case report, so it cannot show how common this cause is for buttock bumps in general
Limitations
only one patient; the buttock lump was a secondary finding in a case where the main presenting problem was an elbow swelling, not an isolated buttock bump
Taken word for word from the abstract
- population An 11-year-old girl presented with a progressive swelling of the right elbow after a contusion.
- population A bone scan revealed increased uptake over the right elbow and the left buttock and acetabulum.
- primaryOutcome Histological findings confirmed the diagnosis of tumoral calcinosis.
- result Four months later, excision of the left elbow and buttock lesions was performed, and histology of both revealed the same diagnosis.
- result There was no evidence of malignancy.
- n An 11-year-old girl presented with a progressive swelling of the right elbow after a contusion.
J Orthop Surg (Hong Kong) · PMID 21519090 · Read it on PubMed ↗
Geng et al. 2011
Large paravaginal angiomyofibroblastoma: magnetic resonance imaging findings
Rare vaginal tumor mimicking a buttock lump.Case seriesVery low qualityRelated question
1 people2011
the mass was identified as angiomyofibroblastoma, a rare benign tumor of the female genital tract, which had grown large enough to present as a buttock lump; it showed distinctive MRI features with uneven signal and strong, patchy contrast enhancement
Who was studied
a woman with a large tumor near the vagina that showed up as a lump in the buttock area
Main outcome
what was causing the buttock mass, based on imaging findings
Quality
this is a single case report of one person, so it cannot show how common this cause of a buttock bump is.
Limitations
only one case; the lump originated from a vaginal-area tumor rather than from buttock or anal tissue itself
Taken word for word from the abstract
- population Angiomyofibroblastoma (AMFB) is a rare, benign, mesenchymal tumor that occurs mainly in the female lower genital tract.
- n We report on a large posterior paravaginal AMFB that presented as a buttock mass
- primaryOutcome describing the magnetic resonance imaging (MRI) features of the disease
- result The tumor displays heterogeneous signal intensity on T2-weighted MRI and fast and persistent inhomogeneous enhancement on dynamic gadolinium-enhanced MRI.
- result We report on a large posterior paravaginal AMFB that presented as a buttock mass
Jpn J Radiol · PMID 21359942 · Read it on PubMed ↗
Paira et al. 2010
Herniation of a broad ligament dermoid cyst through sciatic foramen--a rare cause of gluteal swelling
Rare pelvic cyst herniating into buttockCase seriesVery low quality
1 people2010
the lump was a dermoid cyst from the pelvis (broad ligament) that had pushed through a gap in the pelvic bone (sciatic foramen) into the buttock
Who was studied
35-year-old woman with a slowly growing lump in her buttock
Main outcome
cause of the buttock lump
Quality
this is a single patient case report, so it cannot show how common this cause is.
Limitations
Only one patient was described, so findings cannot be generalized to others with buttock bumps.
Taken word for word from the abstract
- population A 35-year-old lady presented with a slowly growing lump in her left buttock.
- primaryOutcome a slowly growing lump in her left buttock
- result the cyst was found to be arising in between two layers of broad ligament and leaving the pelvis through greater sciatic foramen
- n A 35-year-old lady presented
J Indian Med Assoc · PMID 21121389 · Read it on PubMed ↗
Yu et al. 2010
Osteochondroma of the femoral neck: a rare cause of sciatic nerve compression
Rare bone tumor pressing on nerve.Case seriesVery low qualityRelated question
1 people22 months
Counted as a related question: This study describes a specific rare bone tumor (osteochondroma) causing sciatic nerve compression in one patient, whereas the question asks what could cause a bump on the buttock or anus in general — a much broader diagnostic question about common causes like cysts, hemorrhoids, abscesses, or lipomas.
the buttock mass was a bone tumor (osteochondroma) on the femoral neck pressing on the sciatic nerve
Who was studied
a 39-year-old man with a bump and weakness in the buttock
Main outcome
cause of a nonmobile buttock mass with leg weakness and numbness
Quality
this is a single patient case report, so it cannot show how common this cause is.
Limitations
only one patient was described, so this cause may be very rare and not generalizable.
Taken word for word from the abstract
- population A 39-year-old man presented with weakness and a nonmobile mass in the buttock of 5 months' duration.
- primaryOutcome A pedunculated osseous mass measuring 6x4 cm on the posterior femoral neck was seen on plain radiographs and magnetic resonance imaging.
- result The final pathological report indicated the tumor was an osteochondroma.
- n A 39-year-old man presented with weakness and a nonmobile mass in the buttock of 5 months' duration.
Orthopedics · PMID 20704099 · Read it on PubMed ↗
Chen et al. 2009
Ischiorectal abscess and ischiorectal-vaginal fistula as delayed complications of posterior intravaginal slingplasty: a case report
Bump from mesh-related abscessCase seriesVery low qualityRelated question
1 people2 months
the buttock bump was due to an ischiorectal abscess connected by a fistula to the vagina, arising as a delayed complication of mesh sling surgery
Who was studied
a 48-year-old woman who had prior pelvic prolapse surgery with mesh sling placement
Main outcome
cause of right buttock pain and swelling
Quality
it is a single patient's case report, so it cannot show how common this cause is in people with a buttock bump.
Limitations
single case report with a very specific surgical history, not representative of the general population with a buttock or anal bump
Taken word for word from the abstract
- population A 48-year-old woman with cystocele, uterine prolapse and rectocele had undergone total vaginal hysterectomy, mesh-augmented anterior repair, posterior colporrhaphy and posterior intravaginal slingplasty (IVS) in July 2005.
- primaryOutcome constant right buttock pain and swelling
- result Magnetic resonance imaging confirmed a right ischiorectal fossa abscess and a vaginal fistula.
- result A fistulous tract was found to extend along the intact sling from the vaginal epithelium toward the right ischiorectal fossa.
- n A 48-year-old woman
J Reprod Med · PMID 20677486 · Read it on PubMed ↗
Koga et al. 2010
Anal canal duplication: experience at a single institution and literature review
Rare extra anal canal (congenital).Case seriesVery low qualityRelated question
10 people9.1 years
Counted as a related question: This study examines anal canal duplication, a specific rare congenital anomaly, not the general differential diagnosis of why a bump appears on the buttock or anus in people of any age.
Children had an extra perianal opening in the midline behind the normal anus, usually found incidentally without symptoms; surgical removal of the duplicated canal was curative with no major complications
Who was studied
Infants and young children (all female) with a bump or extra opening near the anus
Main outcome
What anal canal duplication looks like, how it's diagnosed, and how it's treated
Quality
This is a small retrospective case series of only ten patients from one hospital, so it cannot show how common this cause is or compare it to other causes of a bump near the anus.
Limitations
Retrospective chart review, single institution, very small sample, all cases were surgical patients so the full range of presentations outside this center is unknown
Taken word for word from the abstract
- n There were ten cases, all females.
- population Mean age at diagnosis was 6 months (range 0-47 months).
- primaryOutcome The aim of this study was to describe the clinical characteristics, surgical treatment, and outcome of ACD in pediatric cases at a single institution.
- result In all cases, an extraneous perianal orifice opening in the midline posterior to the native anus was present
- result Nine were asymptomatic without any history of perianal infection, identified only incidentally at routine check-up although one case had severe periproctal abscess.
- result The postoperative course was uneventful in all cases and all are well without complications at mean follow-up of 9.1 years (range 5-19 years).
Pediatr Surg Int · PMID 20668865 · Read it on PubMed ↗
Kubota et al. 2010
Usefulness of bFGF spray in the treatment of perianal abscess and fistula-in-ano
Perianal abscess treated, not about causesCase seriesVery low qualityRelated question
9 people14.1 ± 3.2 months
all nine infants improved, with discharge and swelling resolving in about a week, though two had a later recurrence that responded to a repeat course
Who was studied
infant boys with a perianal abscess
What they received
bFGF (basic fibroblast growth factor) spray applied to the abscess
Compared with
none (no comparison group)
Main outcome
resolution of pus discharge and swelling around the abscess
Quality
this is a tiny uncontrolled case series of 9 infants with no comparison group, so it cannot reliably explain why the bump occurs or how well treatment works.
Limitations
no control group, very small sample, all participants were young infant boys, and the study is about treating an already-diagnosed abscess rather than explaining why a bump on the buttock or anus occurs.
Taken word for word from the abstract
- population Nine consecutive males with an average age of 5.1 months (1-9 months) who presented with perianal abscess in the past 2 years
- intervention Two or three sprays of bFGF were applied to the perianal abscess two times a day.
- comparator treated with bFGF (Transfermin, Kaken Co., Ltd., Tokyo, Japan)
- primaryOutcome Pus discharge and local swelling around the fistula subsided within a mean of 7.3 ± 1.9 days
- result All nine patients responded well to the bFGF treatment.
- n Nine consecutive males
Pediatr Surg Int · PMID 20632016 · Read it on PubMed ↗
Sherwani et al. 2010
Haemorrhoids or anal melanoma, importance of preoperative histopathological examination: a case report
Anal bump was actually melanoma, not haemorrhoidsCase seriesVery low qualityRelated question
1 people2010
The lump that looked exactly like prolapsed haemorrhoids on exam turned out to be malignant melanoma when the tissue was examined under the microscope
Who was studied
A woman with a lump at the anus that looked like prolapsed haemorrhoids
Main outcome
What type of lump was causing her classic haemorrhoid-like symptoms
Quality
This is a single patient case report, so it cannot show how common this cause is, only that it can happen.
Limitations
Single case report; no information on how often anal lumps turn out to be melanoma versus haemorrhoids.
Taken word for word from the abstract
- population We report a case of a female with classical clinical presentation of prolapsed haemorrhoids
- n We report a case of a female
- primaryOutcome The clinical presentations of bleeding per rectum, altered bowel habits and a protruding mass are common to both
- result which on histopathological evaluation was found to be malignant melanoma
Pol J Pathol · PMID 20496274 · Read it on PubMed ↗
Yoo et al. 2009
A case of primary psoas abscess presenting as buttock abscess
Buttock bump caused by hidden abscess.Case seriesVery low quality
1 people6 months
the buttock swelling was actually a psoas abscess that had spread from inside the abdomen down into the buttock muscles
Who was studied
a 48-year-old woman with painful swelling of the buttock
Main outcome
cause of the buttock bump/swelling
Quality
this is a single patient case report, so it cannot show how common this cause is or apply broadly to others with a buttock bump
Limitations
only one patient described, so findings may not generalize
Taken word for word from the abstract
- population A 48-year-old woman presented with painful swelling of the buttock with a sense of local heat.
- n A 48-year-old woman presented with painful swelling of the buttock
- primaryOutcome Buttock abscess is a rare clinical manifestation from unusual extrapelvic extension of psoas abscess.
- result Magnetic resonance imaging revealed a large subfascial abscess over the glutei muscles and was traced into the intraabdominal cavity over the iliac wing to the psoas muscle.
- result Psoas abscess could be included in the differential diagnosis of buttock abscess.
J Orthop Traumatol · PMID 19936884 · Read it on PubMed ↗
Pinho et al. 2009
Abnormal advanced hemorrhoidal disease: the need of a staged resection
Severe hemorrhoids caused the bump.Case seriesVery low quality
1 people30th postoperative day
advanced hemorrhoidal disease with giant hypertrophic vascular anal cushions causing protrusion, treated surgically in two stages
Who was studied
a 57-year-old man with severe hemorrhoids causing anemia and bleeding
Main outcome
what caused the anal bump/protrusion and how it was treated
Quality
this is a single patient case report, so it cannot show how common this cause is or apply to people in general
Limitations
only one patient described; a case report cannot establish how often hemorrhoids cause this presentation
Taken word for word from the abstract
- population an unusual case of advanced hemorrhoidal disease in an 57-year-old man presenting with anemia, persistent bleeding, anal protrusion
- n an unusual case
- result advanced hemorrhoidal disease
- result hypertrophic protruded vascular anal cushions
- primaryOutcome anal protrusion
Dis Colon Rectum · PMID 19617767 · Read it on PubMed ↗
Oguzkurt et al. 2008
An uncommon presenting sign of Langerhans cell histiocytosis: focal perianal lesions without systemic involvement
Rare disease (Langerhans cell histiocytosis) causing bump.Case seriesVery low quality
1 people2008
biopsy showed the bumps were caused by Langerhans cell histiocytosis, a rare condition
Who was studied
a 3-year-old boy with constipation and bumps around the anus
Main outcome
what was causing the perianal bumps
Quality
this is a single patient case report, so it cannot tell how common this cause is
Limitations
only one patient; findings may not generalize to other people with a bump on the buttock or anus
Taken word for word from the abstract
- n A 3-year-old boy presented with constipation and perianal lesions resembling condyloma latum.
- population A 3-year-old boy presented with constipation and perianal lesions resembling condyloma latum.
- primaryOutcome The results of a biopsy of the perianal lesions confirmed the diagnosis of Langerhans cell histiocytosis (LCH).
- result The results of a biopsy of the perianal lesions confirmed the diagnosis of Langerhans cell histiocytosis (LCH).
J Pediatr Hematol Oncol · PMID 19131779 · Read it on PubMed ↗
Magdeburg et al. 2008
Perianal abscess caused by Actinomyces: report of a case
Rare bacterial infection causing anal lumpCase seriesVery low quality
1 people2008
The lump was an abscess caused by a rare bacterium called Actinomyces, which produced small yellow 'sulphur granules' found when the area was surgically opened; it was not a fistula, Crohn's disease, tuberculosis, or cancer
Who was studied
a patient with a painless lump and firmness near the anus
Main outcome
underlying cause of the painless perianal lump
Quality
This is a single patient case report, so it cannot show how common this cause is or how it compares to other causes of perianal bumps.
Limitations
Only one patient described; findings cannot be generalized to most people with a perianal bump.
Taken word for word from the abstract
- population The patient had a short history of painless perineal induration without fever or leucocytosis with normal routine blood tests.
- primaryOutcome this rare case of perianal actinomycosis should be kept in mind in the differential diagnosis of a painless perianal mass
- result After excision sulphur granules drained from the cavity and the pathological investigations were indicative of perianal actinomycosis.
- result Primary anorectal actinomycosis and perianal actinomycosis are very rare and are caused by Actinomyces, which is a ubiquitous microaerophilic bacterium.
- n Here we report a case of perianal actinomycosis.
Tech Coloproctol · PMID 19018464 · Read it on PubMed ↗
McAllister et al. 2008
CD34+ pigmented fibrous proliferations: the morphologic overlap between pigmented dermatofibromas and Bednar tumors
Rare pigmented fibrous skin tumor, overlapping with DFSP.Case seriesVery low qualityRelated question
2 people2008
The buttock lesion (and a similar arm lesion) showed a dermal proliferation of spindle cells mixed with pigmented melanocytes, trapping collagen but not fat, and testing positive for CD34 but negative for other markers — features overlapping between a benign pigmented dermatofibroma and a rarer tumor called a Bednar tumor (a pigmented variant of dermatofibrosarcoma protuberans)
Who was studied
Two adults with slowly growing pigmented skin lesions; one was a 31-year-old woman with a pigmented bump on the right buttock
Main outcome
What type of tumor the pigmented bump actually was, based on microscopic and special staining features
Quality
This is a report of just two unusual cases, so it cannot tell you how common this cause is or rule out other explanations for a buttock bump.
Limitations
Only two cases described, one on the arm and one on the buttock, selected because they were unusual and diagnostically ambiguous, not because they represent typical causes of buttock bumps.
Taken word for word from the abstract
- n We report 2 unusual cases of pigmented fibrous proliferations that demonstrate features of dermatofibromas and DFSP.
- population a 31-year-old woman with a 4- to 5-year history of a slowly enlarging, asymptomatic "dark area" on the right buttock
- primaryOutcome Morphologically, both lesions are primarily dermal proliferations of spindled cells admixed with pigmented dendritic melanocytes.
- result By immunohistochemistry, both lesions show focal CD34 positivity but are negative for Factor XIIIa and melanocytic markers.
- result The lesional cells trap collagen fibers at the periphery and there is basal cell hyperpigmentation.
Am J Dermatopathol · PMID 18806495 · Read it on PubMed ↗
Hitora et al. 2009
Ischiogluteal bursitis: a report of three cases with MR findings
Buttock bump caused by bursitisCase seriesLow qualityRelated question
3 people2009
The buttock mass was found to be a bursitis (inflamed fluid sac) near the sit bone, confirmed by MRI and biopsy in two cases; symptoms improved with rest in the third
Who was studied
Three adults (ages 57 to 73) with a painful buttock mass
Main outcome
Cause of a painful buttock mass, diagnosed by MRI and tissue exam
Quality
This is a report of only three patients with no comparison group, so it cannot show how common this cause is.
Limitations
Very small number of cases (n=3), no control group, and findings may not generalize to all buttock bumps.
Taken word for word from the abstract
- population Three cases of ischiogluteal bursitis in a 57-year-old man, a 73-year-old woman and a 73-year-old man are presented.
- primaryOutcome All patients presented with a gradually increasing, painful buttock mass.
- result Two patients underwent excision of the lesion, which was histologically diagnosed as ischiogluteal bursitis. One patient was conservatively treated and the symptoms gradually decreased.
- n Three cases of ischiogluteal bursitis in a 57-year-old man, a 73-year-old woman and a 73-year-old man are presented.
Rheumatol Int · PMID 18712394 · Read it on PubMed ↗
Cashell 2008
Apocrine adenoma of the breast
Rare benign tumor type can occur in perianal areaCase seriesVery low qualityRelated question
1 peopletwo years
The lump was a rare benign breast tumor called apocrine adenoma, made of tightly packed tubules; it has not come back after two years
Who was studied
a 47-year-old woman with a breast lump
Main outcome
what the lump was found to be
Quality
This is a single case report about a breast tumor, not specifically about buttock or anal bumps, so it gives very limited and indirect information for this question.
Limitations
Single case report of a breast tumor; only briefly mentions that similar tumors have been reported in the perianal region, without details about those cases.
Taken word for word from the abstract
- population A left breast nodule from a 47-year-old female was found by mammography and excised.
- primaryOutcome The tumor was well circumscribed and composed of tightly packed tubules lined by cells with apocrine features.
- result There has been no recurrence in two years.
- result Apocrine adenomas have been reported arising in a variety of sites including the breast, (1-5) perianal region, (6,7) eyelid, (8) and axilla. (9)
- n A left breast nodule from a 47-year-old female was found by mammography and excised.
W V Med J · PMID 18491794 · Read it on PubMed ↗
Sugishita et al. 2008
Fournier's gangrene progressing from the buttocks to the scrotum following a perianal abscess
Abscess turned into severe gangrene.Case seriesLow qualityRelated question
1 people2008
severe swelling of the scrotum, with crepitation, redness, and partial necrosis progressed rapidly
Who was studied
A 61-year-old man
Main outcome
Progression of a perianal abscess to a severe infection
Quality
It's a single patient's case report, so it can't show how common this cause is or compare it to other explanations.
Limitations
Only one patient described, with a severe and rare complication (Fournier's gangrene) rather than a typical uncomplicated bump.
Taken word for word from the abstract
- population A 61-year-old man was admitted to our hospital complaining of perineal pain and was found to have a perianal abscess.
- n A 61-year-old man was admitted to our hospital
- primaryOutcome Although the perianal abscess was drained and antibiotic treatment started, severe swelling of the scrotum, with crepitation, redness, and partial necrosis progressed rapidly.
- result severe swelling of the scrotum, with crepitation, redness, and partial necrosis progressed rapidly
J Infect Chemother · PMID 18297451 · Read it on PubMed ↗
Michelow et al. 2008
The utility of fine needle aspiration in HIV positive children
Cause of buttock lumps not specifiedRetrospectiveLow qualityRelated question
91 people2008
Across all children, lumps were due to reactive lymph nodes, tuberculosis-type infection, abscess, fungal infection, lymphoma, Kaposi sarcoma and other rarer causes, but the abstract does not state which of these caused the three buttock masses specifically
Who was studied
HIV positive children aged 15 years and younger who had needle biopsies of lumps, including three with buttock masses
Main outcome
What the lump turned out to be after needle biopsy (fine needle aspiration)
Quality
This is a small retrospective series focused on HIV-positive children overall, with only three buttock cases and no breakdown of what those specific lumps were.
Limitations
Very small subgroup with buttock masses (3 of 91 children), no diagnosis given specifically for the buttock masses, and population restricted to HIV-positive children, not general people with a buttock or anal bump.
Taken word for word from the abstract
- population 91 children aged 15 years and younger who were known to be infected with the human immunodeficiency virus (HIV)
- primaryOutcome To determine the spectrum of disease, diagnostic accuracy and adequacy of fine needle aspirates (FNA)
- result buttock masses in three children
- result Reactive lymphadenopathy was diagnosed in 42 cases, mycobacterial infection in 22, four children were diagnosed with abscess, one child had a fungal infection and five were found to have non-Hodgkin's lymphoma.
- n 95 FNAs were performed in 91 children
Cytopathology · PMID 17916096 · Read it on PubMed ↗
Bessa 2007
Results of the lateral advancing flap operation (modified Karydakis procedure) for the management of pilonidal sinus disease
Describes pilonidal sinus surgery, not cause of bump.Case seriesLow qualityRelated question
82 people20 +/- 6.8 months
low complication rate (7.3%), short hospital stay, and no recurrences over about 20 months follow-up
Who was studied
patients with pilonidal sinus disease (a cyst/tunnel near the tailbone)
What they received
modified Karydakis flap surgery
Compared with
none (no comparison group)
Main outcome
surgical complications and recurrence of the pilonidal sinus
Quality
this is a single-group surgical case series without a comparison group, so it cannot determine why the bump occurs, only how surgery for an already-diagnosed pilonidal sinus performed.
Limitations
No control group; study is about surgical treatment outcomes, not about explaining the cause of a buttock/anal bump.
Taken word for word from the abstract
- population The present study included 82 consecutive patients.
- intervention The modified technique was applied in all patients.
- comparator The present study included 82 consecutive patients.
- primaryOutcome Patients were followed up by physical examination to detect recurrence.
- result No recurrences were encountered throughout the 20 +/- 6.8 months mean follow-up duration.
- n The present study included 82 consecutive patients.
Dis Colon Rectum · PMID 17828399 · Read it on PubMed ↗
Soulier et al. 2007
[An unusual perianal abscess]
Rare benign tumour, not abscess.Case seriesVery low quality
1 people2007
the bump was a rare benign soft-tissue tumour called aggressive angiomyxoma, not an abscess
Who was studied
a 58-year-old woman with a lump near the anus mistaken for an abscess
Main outcome
what the bump turned out to be
Quality
this is a single patient case report, so it cannot show how common this cause is.
Limitations
only one case is described, diagnosis was initially wrong, and such tumours are reported to be very rare (only 130 cases known).
Taken word for word from the abstract
- population a 58-year-old woman, presenting with a pelvi-perineal mass, which was considered to be an anal abscess
- n We report the case of a 58-year-old woman
- primaryOutcome After surgical excision, an AA was diagnosed, with classical histological features
- result Aggressive angiomyxoma (AA) is a mesenchymal tumour occurring in connective tissue of the perineum or lower pelvis
- result After surgical excision, an AA was diagnosed, with classical histological features (myxoid and vascular components) and which was positive for vimentin and CD34.
Gastroenterol Clin Biol · PMID 17273138 · Read it on PubMed ↗
Rai et al. 2005
Tuberculous gluteal abscess coexisting with scrofuloderma and tubercular lymphadenitis
Buttock bump caused by tuberculosis infection.Case seriesVery low quality
1 people12 months
The buttock bump was caused by tuberculosis infection (a tuberculous abscess with skin and lymph node involvement), confirmed by biopsy culture showing Mycobacterium tuberculosis
Who was studied
23-year-old man with a swollen buttock and skin lesions oozing fluid
Main outcome
What caused the buttock swelling and skin lesions
Quality
This is a single patient case report, so it cannot show how common this cause is or apply broadly to others with similar bumps.
Limitations
Single case report; no comparison group; findings may not generalize to other causes of buttock bumps.
Taken word for word from the abstract
- population A 23-year-old man presented with diffuse swelling of the left buttock with overlying skin lesions associated with seropurulent discharge.
- primaryOutcome culture of skin biopsy showed Mycobacterium tuberculosis
- result culture of skin biopsy showed Mycobacterium tuberculosis. Skin and lymph node biopsy showed granulomatous inflammation suggestive of tuberculosis.
- n A 23-year-old man presented
Dermatol Online J · PMID 16409910 · Read it on PubMed ↗
Gupta 2005
Novel approach to advanced hemorrhoidal disease
Describes hemorrhoid surgery outcomes, not bump causes.RetrospectiveLow qualityRelated question
1,650 people2005
The procedure had a short recovery time, and late complications such as anal tags, anal papillae and recurrence occurred in 2% of patients; the study does not explain what causes a bump on the buttock or anus.
Who was studied
People with advanced hemorrhoids who underwent a surgical procedure
What they received
Radiofrequency ablation of hemorrhoids with suture fixation of the hemorrhoidal mass
Main outcome
Complications and recovery after the procedure (urine retention, wound infection, perianal thrombosis, anal tags, recurrence)
Quality
It is a non-randomized, retrospective case series without a comparison group, so it can describe treatment outcomes but cannot reliably explain why a bump occurs.
Limitations
Non-randomized, retrospective design with no control group; focuses on surgical outcomes for hemorrhoids rather than on explaining the cause of a bump near the buttock or anus.
Taken word for word from the abstract
- n performed in 1650 patients over a period of 5 years
- population This non-randomized, retrospective study describes the clinical outcome of the procedure performed in 1650 patients over a period of 5 years.
- intervention A novel technique of hemorrhoidal ablation by radiofrequency is described, which is followed by suture fixation of the hemorrhoidal mass.
- primaryOutcome The immediate postoperative complication included retention of urine, wound infection and perianal thrombosis.
- result Late complications included development of anal tags, anal papillae and recurrence in 2% patients.
Rom J Gastroenterol · PMID 16400352 · Read it on PubMed ↗
Porzionato et al. 2005
Perianal and vulvar Crohn's disease presenting as suspected abuse
Crohn's disease caused perianal swellingCase seriesVery low quality
1 people2005
Biopsies of the vulva and rectum showed granulomas consistent with Crohn's disease affecting the genital skin, explaining the perianal fissures and swelling that had been mistaken for abuse
Who was studied
a 7-year-old girl with perianal fissures and swelling of the labia majora
Main outcome
underlying cause of the perianal and vulvar swelling/fissures
Quality
This is a single case report, so it cannot show how common this cause is or apply broadly.
Limitations
Only one patient is described, and the abstract gives no information on how often this cause occurs.
Taken word for word from the abstract
- population a 7-year-old girl who was referred by her general paediatrician to the local hospital for perianal fissures and swelling of the labia majora
- primaryOutcome histopathologic examination of vulvar and rectal biopsies revealed multiple non-caseating and non-confluent epithelioid-gigantocellular granulomas, consistent with a diagnosis of Crohn's disease, with cutaneous involvement of the genitalia
- result histopathologic examination of vulvar and rectal biopsies revealed multiple non-caseating and non-confluent epithelioid-gigantocellular granulomas, consistent with a diagnosis of Crohn's disease, with cutaneous involvement of the genitalia
- n a 7-year-old girl
Forensic Sci Int · PMID 16216708 · Read it on PubMed ↗
Kazakov et al. 2005
Pseudoangiomatous stromal hyperplasia in lesions involving anogenital mammary-like glands
Benign gland tissue overgrowth caused bumpCase seriesVery low quality
3 peopleone and three years
The nodules were found to contain pseudoangiomatous stromal hyperplasia (PASH) of anogenital mammary-like glands, sometimes together with a fibroadenoma or phyllodes tumor
Who was studied
women with a solitary nodule in the perianal area, perineum, or labial area
Main outcome
what caused the nodule under the microscope
Quality
Only three case reports with no control group, so it just shows this cause is possible, not how common it is.
Limitations
Very small number of cases, only two had any follow-up, and the lesions were already surgically removed before being examined, so this does not show how to diagnose or manage such a bump without surgery.
Taken word for word from the abstract
- population All patients were females (ages, 42, 43, and 53 years). Each presented with a solitary, 1.5- to 2-cm asymptomatic nodule. Locations included the perianal area, perineum, and labium majus.
- n We present three cases of lesions involving anogenital mammary-like glands demonstrating this feature.
- primaryOutcome Histopathologically, one lesion was classified as low-grade phyllodes tumor, another as fibroadenoma, and in the remaining case PASH was found in the background of mild hyperplasia of anogenital mammary-like glands and substantial lipomatous metaplasia.
- result PASH has not been previously described in the anogenital area, this feature seems to have been either overlooked or is genuinely rare in this location. It may occur in a preexisting lesion of anogenital mammary-like glands or may apparently by itself produce a clinically detectable lesion.
- followUp Two patients with follow-up were disease-free at one and three years after the operation.
Am J Surg Pathol · PMID 16096415 · Read it on PubMed ↗
Coremans et al. 2005
Actinomycosis, a rare and unsuspected cause of anal fistulous abscess: report of three cases and review of the literature
Rare bacterial infection causing fistula or massCase seriesVery low quality
3 people2005
The bumps were caused by infection with Actinomyces bacteria, presenting as a simple fistula-in-ano or a mass, with the infection spreading into the scrotum in all three cases; diagnosis was confirmed by finding sulfur granules and histology
Who was studied
People with a mass or fistula near the anus that turned out to be caused by a rare bacterial infection called actinomycosis
Main outcome
What caused the anal/perianal mass or fistula
Quality
Only three cases plus a literature review, so it cannot tell how common this cause is, only that it is possible.
Limitations
Very small number of cases (three), retrospective comparison to a literature search rather than a systematic study, and the authors note the findings contrast with the 'classic picture' of this condition.
Taken word for word from the abstract
- population Primary perianal actinomycosis is rare.
- primaryOutcome The diagnosis is a challenge and often delayed, with a protracted history of masses and sinuses extending into the gluteal and genital region.
- result The lesions, a simple fistula-in-ano or a mass, were diagnosed in an early stage in all three patients. The infection always spread into the scrotum.
- result The diagnosis was suspected by the observation of draining sulfur granules and promptly confirmed by histology in the three cases.
- n We report three cases and compare their characteristics to those of published cases
Dis Colon Rectum · PMID 15875298 · Read it on PubMed ↗
Flint et al. 2004
Rectal duplication cyst presenting as perianal sepsis: report of two cases and review of the literature
Rare congenital cyst causing the lumpCase seriesVery low qualityRelated question
2 peoplenot specified beyond 'follow-up' with no duration given
Counted as a related question: This study examines a specific rare congenital condition (rectal duplication cyst) as a cause of perianal problems, rather than helping someone understand what kinds of bumps on the buttocks or anus are and their common causes.
The bump was a rectal duplication cyst, a rare congenital lesion causing recurrent perianal infection; after full surgical removal there were no complications and no recurrence, and the tissue was not cancerous
Who was studied
two middle-aged women with recurring infection and a lump near the anus
Main outcome
what was causing the perianal lump/infection and what happened after it was surgically removed
Quality
This is a report of only two patients, so it cannot tell you how common this cause is or what usually happens.
Limitations
Only two cases are described, both middle-aged women, limiting how much this can be generalized to other people with a similar bump.
Taken word for word from the abstract
- population We present two cases of middle-aged females who presented with perianal sepsis secondary to rectal duplication cyst.
- primaryOutcome The second case presented with a perineal mass after a bout of perianal inflammation.
- result Rectal duplication cyst is a rare cause of recurrent perianal sepsis that should be considered in difficult cases, especially in those with associated musculoskeletal anomalies.
- result There were no complications postoperatively and no recurrence at follow-up. Histopathology revealed no malignancy in the cyst.
- n We present two cases of middle-aged females who presented with perianal sepsis secondary to rectal duplication cyst.
Dis Colon Rectum · PMID 15657675 · Read it on PubMed ↗
Pini Prato et al. 2004
Feasibility of perineal sagittal approaches in patients without anorectal malformations
Describes surgery, not bump causesCase seriesVery low qualityRelated question
10 people2 years (for the patient who died)
No surgical complications occurred; cosmetic results were excellent and continence was satisfactory in all patients, though one patient with a malignant tumor later died of the disease
Who was studied
Children without anorectal malformations who had various perianal/pelvic conditions (abscesses, strictures, tumors, developmental anomalies) needing surgery
Main outcome
Surgical complications, cosmetic appearance of the perineum, and continence after surgery
Quality
This is a very small retrospective case series of only 10 patients describing a surgical technique, not a study explaining why bumps occur near the anus or buttock.
Limitations
Retrospective, very small sample size, mixes many different unrelated diagnoses (including malignant teratoma and rhabdomyosarcoma which are not part of this question), and focuses on surgical technique rather than explaining causes of perianal bumps.
Taken word for word from the abstract
- population We retrospectively evaluated 10 patients consecutively operated on via a perineal sagittal approach, with or without sphincteric structure involvement, between January 1997 and December 2001. All of these patients were without ARM.
- n We retrospectively evaluated 10 patients
- primaryOutcome The parameters that we analysed included technical details, possible complications, perineal cosmetic appearance, and outcome.
- result No complications were experienced. The postoperative cosmetic perineal appearance was excellent in all patients, and continence, when assessed, was always considered satisfactory.
- result one patient with malignant sacrococcygeal teratoma died as a result of the malignant process 2 years after surgery
Pediatr Surg Int · PMID 15517290 · Read it on PubMed ↗
Schiera et al. 2004
Perianal condyloma-like lesions in multiple myeloma associated amyloidosis
Myeloma-related amyloid deposits, not wartsCase seriesVery low quality
1 people2004
The perianal bumps were caused by amyloid deposits from multiple myeloma, not genital warts
Who was studied
A 57-year-old woman with multiple myeloma
Main outcome
Cause of perianal bumps (condyloma-like lesions)
Quality
This is a single case report, so it cannot show how common this cause is or apply to people in general.
Limitations
Single case report; findings may not generalize beyond this one patient.
Taken word for word from the abstract
- population a 57-year-old woman who was diagnosed as having multiple myeloma IgG lambda
- primaryOutcome Pedunculated condylomatous tumours began to develop in the perianal area.
- result The excisional biopsy of a perianal nodule revealed a faintly eosinophilic, amorphous material replacing almost the entire dermis, in association with ectatic, endothelial-lined vascular spaces. The dermal deposits showed affinity with Congo Red stain. There were no histopathological features typical of condylomata acuminata. A diagnosis of cutaneous myeloma-associated amyloidosis was established.
- n a 57-year-old woman
Eur J Dermatol · PMID 15246949 · Read it on PubMed ↗
Van Mieghem et al. 2004
Ischiogluteal bursitis: an uncommon type of bursitis
Rare bursa swelling causing buttock bumpCase seriesVery low quality
size not given2004
The bump was found to be a rare, under-recognized swelling called ischiogluteal bursitis, which can look similar to other benign or malignant soft-tissue tumors on imaging
Who was studied
people with a soft tissue mass or bump in the buttock region
Main outcome
identifying the cause and imaging appearance of a buttock bump
Quality
This is a single case report describing imaging findings, so it cannot show how common or typical this cause of a buttock bump is.
Limitations
Only one case is described, with no information on how many people this applies to or how it compares to other causes of buttock bumps.
Taken word for word from the abstract
- population Ischiogluteal bursitis is a rare, infrequently recognized soft tissue mass of the buttock region.
- primaryOutcome We describe the imaging findings of bursitis.
- result Of importance is the radiological differential diagnosis with other benign and malignant soft-tissue tumors.
Skeletal Radiol · PMID 15138722 · Read it on PubMed ↗
Knuttel et al. 2003
A cerebriform mass on the right buttock
Rare benign fat tumor under skinCase seriesVery low quality
size not given2003
The bump was a rare benign fatty skin tumor called nevus lipomatosus cutaneosus superficialis, made of mature fat cells in the skin, which had grown very large and was surgically removed
Who was studied
A patient with a large bump on the right buttock and thigh
Main outcome
Cause and treatment of the buttock mass
Quality
This is a single case report, so it cannot tell us how common this cause is or what usually happens.
Limitations
Only one patient was described, so findings may not generalize; no comparison group or long-term outcome data beyond this case.
Taken word for word from the abstract
- population Wide excision of the right thigh and buttock mass was performed
- primaryOutcome To illustrate by a case report the clinical presentation and management of this rare condition.
- result Nevus lipomatosus cutaneous superficialis of Hoffmann-Zurhelle (NLCS) is a rare disorder that is characterized by tumors of mature fat cells situated within the dermis.
- result The largest measured nevus lipomatosus, congenital type (20 x 30 cm), was removed from this patient.
Dermatol Surg · PMID 12828707 · Read it on PubMed ↗

How we searchedThe exact query, the date it ran, and what came back — so you can run it yourself.

Searched: PubMed · ClinicalTrials.gov · Crossref on 2026-10-26
The exact search — paste this into PubMed to repeat it: (perianal[tiab] OR "anal canal"[tiab] OR buttock[tiab] OR "natal cleft"[tiab] OR "intergluteal cleft"[tiab]) AND (bump[tiab] OR lump[tiab] OR mass[tiab] OR nodule[tiab] OR swelling[tiab]) AND ("Pilonidal Sinus"[Mesh] OR "Hemorrhoids"[Mesh] OR "Skin Tags"[tiab] OR "Condylomata Acuminata"[Mesh] OR "Molluscum Contagiosum"[Mesh] OR "Abscess"[Mesh] OR "Folliculitis"[Mesh] OR "Diagnosis, Differential"[Mesh]); PubMed expanded that to: ("perianal"[Title/Abstract] OR "anal canal"[Title/Abstract] OR "buttock"[Title/Abstract] OR "natal cleft"[Title/Abstract] OR "intergluteal cleft"[Title/Abstract]) AND ("bump"[Title/Abstract] OR "lump"[Title/Abstract] OR "mass"[Title/Abstract] OR "nodule"[Title/Abstract] OR "swelling"[Title/Abstract]) AND ("Pilonidal Sinus"[MeSH Terms] OR "Hemorrhoids"[MeSH Terms] OR "Skin Tags"[Title/Abstract] OR "Condylomata Acuminata"[MeSH Terms] OR "Molluscum Contagiosum"[MeSH Terms] OR "Abscess"[MeSH Terms] OR "Folliculitis"[MeSH Terms] OR "diagnosis, differential"[MeSH Terms])
What came back: 256 records found · 200 read · 108 answered the question
Included: Human, animal or laboratory studies reporting an outcome relevant to the question
Excluded: Records about a different condition or intervention
Studies mainly about anal cancer (malignant mass)
Studies mainly about rectal prolapse
Studies mainly about genital herpes ulcers
Studies mainly about vaginal or vulvar bumps
Studies mainly about scrotal or groin lumps
Studies mainly about sacrococcygeal teratoma (congenital mass)
Records reporting no outcome
Retracted publications, which are listed but excluded from every count
Limits: Details were read from abstracts, not full papers, so anything reported only in a paper's methods section is not captured here.
Fields were read from abstracts, not full text, so detail reported only in a paper's methods section is not captured.
Evidence strength is adapted from the GRADE framework. It is not a GRADE assessment and was not produced by a GRADE panel.

256records came back from the search
200were read
108actually answered the question

Risks and safetyReported side effects and who should be careful.

Case reports describe perianal abscesses progressing to severe, fast-moving infections (Fournier's gangrene) if not treated promptly.
A lump that looked and felt exactly like ordinary hemorrhoids turned out, after tissue testing, to be a melanoma (skin cancer) in one case, and a cancerous growth in another case of a wart-like bump.
Several benign look-alike conditions (cysts, bursitis, benign tumors) needed imaging or a biopsy to be told apart from more worrying causes, meaning a bump often cannot be diagnosed by appearance alone.

Why people askWhat brings people to this question.

A new bump near the anus or buttock crease is often painful, itchy, or makes sitting uncomfortable, which pushes people to search for an explanation before seeing a doctor.
The area feels embarrassing to show a doctor, so many people try to self-diagnose online first.
A sudden lump can be frightening, and people want to rule out something serious like cancer.
Some bumps keep coming back, and people want to know if it's the same problem recurring or something new.

Common questionsShort answers, drawn from the same studies.

Why is there a bump on my butthole?: Studies describe several possible causes of a bump right at the anus, most commonly hemorrhoids (swollen blood vessels), abscesses (infected pus pockets), or skin tags; less often, it's a wart-like growth caused by HPV. Because these can look similar, a doctor needs to examine it to tell them apart.
Why is there a bump at the top of my bum crack?: A bump right at the top of the buttock crease, near the tailbone, is the classic location for a pilonidal cyst — a pit where hair gets trapped under the skin and causes inflammation. Studies found this type of cyst is more common in people with a deeper buttock crease.
Why do I keep getting bumps on my butt?: Bumps that keep recurring in the same spot are often linked to conditions like pilonidal sinus disease or hidradenitis suppurativa (a condition causing recurring boil-like lumps), both described here as tending to come back even after treatment. If bumps keep returning, a doctor can check which of these, or something else, is responsible.
Why do I have bumps on my inner butt cheeks?: The studies in this review describe a wide range of possible buttock lumps, from common cysts and infections to rarer benign tumors, mostly reported as single cases. No study pins down how common each cause is on the inner buttock specifically, so this is an area where seeing a doctor is the only way to know for sure.
When should I see a doctor about a bump near my anus?: See a doctor if the bump is painful, growing, bleeding, discharging pus, or not going away, since case reports describe rare but serious look-alikes such as abscesses that can spread rapidly, or tumors that mimic hemorrhoids. A clinical exam, and sometimes a biopsy, is the only reliable way to tell a harmless bump from something that needs treatment.

What has changedEvery re-check, and whether it changed the answer.

2026-10-26
Clear the 'Under re-review' backlog: rebuild every remaining first-method (ev-1) page under the current method. 99 new studies · 124 no longer retrieved · evidence strength very low → low · conclusion signal of harm → not applicable.
How certain we are changed. The conclusion changed.

This is information, not advice

This page summarises published research. It cannot tell you what is happening in your own body, and evidence changes. If something is bleeding, painful, or new, it is worth being looked at — that is a different question from the one on this page, and a better one to bring to a consultation.

Contact the office

Automated evidence review — PubMed, ClinicalTrials.gov, Crossref. Search strategy, grading rules and the checks that must pass before anything publishes were written by Allen Kamrava, MD, MBA, FACS, FASCRS, colon & rectal surgery, Beverly Hills. The pages themselves are compiled by software running that method and are not read one by one before publication — saying otherwise would be the one claim here that could not be checked.

Allen Kamrava, MD, MBA, FACS, FASCRS · 435 N. Bedford Dr., Suite 308, Beverly Hills, CA 90210 · 424.279.8222

Educational information — not medical advice.