Mole on Buttocks: Where to Look and What to Watch

Several factors limit attention to buttock moles:

Not visible without a mirror or specific positioning.

Not routinely shown to a dermatologist unless explicitly examined.

Covered by clothing essentially all the time.

Not a high-anxiety location culturally — people don't think 'cancer' about this area as readily as the face or chest.

The combined result is that buttock moles can be present and changing for years before being noticed. Melanoma on the buttocks is uncommon but real, and the worst-case scenario is a mole that has been changing for years before someone notices.

The fix is methodical: monthly buttock check during self-exam, partner help when available, and dermatology inclusion of buttock examination during routine visits.

Common findings:

Benign nevi. Same as elsewhere — stable, well-defined moles. Often present since adolescence.

Seborrheic keratoses. 'Stuck-on' brown waxy growths in adults. Benign.

Skin tags in skin folds.

Post-inflammatory hyperpigmentation from healed pimples, ingrown hairs, or sitting-related friction.

Pilonidal sinus or cyst (in the upper buttock cleft). Not a mole; can be associated with inflammation, drainage, or pain.

Molluscum contagiosum (in some patients).

Less common but important:

Melanoma. Same ABCDE features as elsewhere.

Basal cell carcinoma. Less common on buttocks but possible.

Squamous cell carcinoma. Less common on covered skin.

Methods for monthly self-exam:

Full-length mirror plus hand mirror. Stand with back to full-length mirror, hold hand mirror, angle and turn to see all areas.

Phone camera. Hold phone behind you, take photos of each buttock and the cleft area. Review on screen.

Partner check. A partner can look during shower or dressing. They can describe what they see; you can ask follow-up questions.

Lying down with mirror. On stomach, hand mirror over shoulder.

After shower with bright lighting and good vision is the most practical time. Photograph anything notable with a coin or ruler for scale.

For each buttock, note:

All moles you can identify, including their approximate location.

Any that look new, growing, or different from your other moles.

Any non-healing sores, scabs, or persistent rashes.

Within 2-4 weeks if any:

New buttock mole that has appeared in the past 6-12 months.

Mole that has changed in size, shape, or colour.

Irregular borders, multiple colours.

Diameter over 6mm.

Ugly duckling: distinctly different from your other buttock moles.

Within 1-2 weeks if any:

Non-healing scab, ulcer, or sore on buttocks.

Bleeding without trauma.

Rapidly growing lesion.

Lesion that has been there for a while but you cannot remember when it appeared.

For someone in higher-risk groups (prior melanoma, family history, atypical mole syndrome), specific examination of buttock moles by a dermatologist is part of full-body skin checks. Ask explicitly if you are not sure whether they were checked.

The buttocks experience friction from sitting, exercise, and tight clothing. Friction-related issues:

Folliculitis (infected hair follicles). Red bumps, sometimes with pus heads. Treatable with hygiene and topical treatments.

Ingrown hairs. Common in shaved or waxed areas. Resolve with topical treatment.

Post-inflammatory hyperpigmentation from healed folliculitis or ingrown hairs.

Keratosis pilaris. Small bumps from blocked hair follicles. Benign.

Friction patches from chronic sitting or tight clothing.

Most of these are not melanoma concerns. They can be confused with moles in early appearance, but most resolve with appropriate care or remain stable.

If a 'pimple' or 'bump' has been on the buttocks for more than 6 weeks without resolving, evaluate. Persistence beyond normal acne or folliculitis timelines is a flag.

Moles in friction zones (under tight waistbands, in skin folds) may be irritated and difficult to monitor. If a mole is chronically irritated and you cannot reliably tell if it's changing, dermatology evaluation is appropriate. Sometimes removal makes monitoring easier and resolves discomfort.

Annual full-body dermatology should include buttock examination. Mention this specifically if your previous experience has been only quick visual checks of more visible areas.

For anyone with:

Prior melanoma anywhere.

Family history of melanoma.

More than 50 moles total.

Fair skin with significant sun exposure history.

Immunosuppression.

A 6-monthly examination including buttocks is reasonable.

For any specific buttock lesion that worries you, schedule within 2-4 weeks. Bring photos if you have baseline. Tell the dermatologist exactly what concerns you about the lesion.