Noticing a lump on the anogenital skin is a common reason for people to attend a genitourinary medicine clinic. The person might be convinced that the lump is new, but it is often the case that the lump has been there for some time and for some reason the person has only recently become aware of it.
History of presenting complaint
• Clarify what they mean by a Tump’ some people might describe something that sounds more like an ulcer.
• Where exactly is the lump?
• How long has it been there?
• Are there any associated symptoms such as pain, itching or bleeding?
• Do they have any symptoms elsewhere such as generalized itch?
• Have they had any significant ill health in the past or any sexually transmitted infections?
• Take a drug history. Have they tried treating the lump with anything?
As with any genital complaint, a sexual history is essential. This might reveal that the lump could be due to an STI but you could find that the person has never had sexual contact. The history might give you a clue as to why the person has only just noticed the lump — guilt or anxiety about a sexual encounter is a common reason for people starting to pay more attention to their genitals.
If the history suggests that they could have acquired an STI, offer them an STI screen.
The lump might be immediately obvious but, if it is not, ask the person to point it out to you. See Table Clinical features of genital skin lumps for the clinical features of various types of genital skin lumps.
Table Clinical features of genital skin lumps
Normal or sexually acquired
|Normal findings or variants||1-mm-diameter smooth pale papules, sometimes filiform, in a ring around the penile corona||Coronal papillae, aka penile pearly papules||Explain that they are normal and that no treatment is needed|
|1 -mm-diameter smooth whitish papules either side of the penile frenulum, usually symmetrical||Tyson’s glands: modified sebaceous glands||Explain that they are normal and that no treatment is needed|
|Pale, yellowish punctate appearance under the skin surface, made more obvious by stretching the skin. Usually seen on the underside of the foreskin or the labia minora||Fordyce spots: sebaceous glands||Explain that they are normal and that no treatment is needed|
|Filiform surface on lateral sides of vaginal introitus, usually flesh coloured||Vulval papillomatosis||Explain that this is normal and that no treatment is needed|
|Pale, often yellowish papules usually 2-3 mm across but can be up to 10 mm. Most common on scrotum and penile shaft but also seen on labia majora||Sebaceous glands. If larger, they have probably hypertrophied as a result of being picked or have become infected||They are normal and should not be picked|
|Soft, smooth fleshy tissue at the inner margin of the vulvar vestibule||Hymenal remnants||Explain that this is normal and that no treatment is needed|
|Probably sexually acquired||3-10 mm, red, often flaky papules/nodules on scrotum, penile shaft or vulva. Person complaining of generalized itch. Might be a fine macular rash on trunk. Linear scaly appearance on finger webs or inner aspect of wrists||Scabies||See site for further information and management advice|
|Roughened papules, often slightly paler than surrounding skin. Found anywhere in anogenital region but common at posterior fourchette (the side of the vagina closest to the perineum) and around the foreskin. Also seen in the urethral meatus and perianally. On thin mucosa, the capillary pattern can be seen within them. Vary in size from barely visible to a few centimetres across||Anogenital warts||See site for further information and management advice|
|Smooth papules, often with a central depression (hard to see on small ones). Seen anywhere on anogenital skin, including lower abdomen and pubic area. Usually 2-8 mm in diameter, occasionally bigger if patient is immunosuppressed||Molluscum contagiosum||See site for further information and management advice|
|Hard fleshy lesions in perianal area or vaginal introitus. Risk group for syphilis, e.g. contact with someone from a country where syphilis is common, or men who have sex with men (MSM). Probably has a macular rash elsewhere on body||Condylomata lata. A sign of secondary syphilis||See site for further information and management advice|
|Fluid-filled blisters or pustules, usually tender, might have tender inguinal lymphadenopathy. Often slight redness and swelling around the lesions. Might have flu-like symptoms||Herpes||See site for further information and management advice|
|Other conditions||Usually solitary subcutaneous nodule, flesh-coloured unless infected. Seen anywhere except subpreputially and in the vaginal introitus||Epidermoid cyst, aka sebaceous cyst||Usually best left alone. If enucleated by squeezing, the material simply reaccumulates. If large and inconvenient, they can be surgically removed. If infected, antibiotics, e.g. flucloxacillin 500 mg q.i.d. 7 days (unless penicillin allergic), can reduce inflammation|
|Roughened papules, usually slightly darker than surrounding skin. Found almost anywhere on body. Not usually seen subpreputially or in the vaginal introitus. More common in older people. Usually have a slightly greasy surface (though this is hard to feel when wearing gloves!)||Basal cell papilloma, aka sebaceous wart||Can be left untreated. If treatment required for cosmetic reasons or due to concern that it is a viral wart, cryotherapy is effective|
|Indurated, erythematous skin with pustules. Sometimes inguinal lymphadenopathy. Seen anywhere||Furunculosis||Swab pustules. Often requires systemic antibiotics. Usually caused by S. aureus so try flucloxacillin 500 mg q.i.d. 7 days (unless penicillin allergic)|
|Pustules at hair follicles. Seen in any site. In genital area usually seen in pubic region||Folliculitis||Topical antiseptic or antibiotic (e.g. mupirocin ointment) usually adequate|
|1-2 mm, red maculopapules usually seen on scrotum. Non-tender||Angiokeratomata||No treatment needed.|
Hopefully by now you have made a diagnosis and decided on treatment or referral. If in doubt refer to a genitourinary medicine physician or dermatologist. Some hospitals have special clinics for penile or vulval dermatology staffed by specialists from both departments (and often a gynaecologist or urologist).
If you find that the lump is a normal variant, you might be able to relate the patient’s concern to an episode in their history such as sex outside a long-term relationship that has made them concerned about STIs. If you think that the lump is due to an STI, then as well as offering the appropriate treatment it is important to recommend tests for other infections that could have been acquired from the same encounter.