Penile Cancer

Pearly penile papules (papillomas) — normal findings on the glans or corona; no treatment needed.
Zoon balanitis (plasma cell balanitis / balanitis plasmacellularis) — occurs in uncircumcised men from the 3rd decade onward as smooth, moist, erythematous, well-circumscribed plaques on the glans, often with shallow erosions and up to 2 cm in size; can be difficult to distinguish from carcinoma in situ. Histology shows angiofibromas (like the facial lesions of tuberous sclerosis) with a plasma cell infiltrate. Diagnose by biopsy (exclude malignancy and extramammary Paget's). Circumcision is curative in most cases; for patients avoiding it, topical corticosteroids relieve symptoms, and topical calcineurin inhibitors (tacrolimus, pimecrolimus) or laser may help.

Bowenoid papulosis — multiple reddish-brown verrucous papules on the penile shaft, typically in young men; histologically resembles low-grade carcinoma in situ (Bowen's disease) and is linked to HPV 16. Progression to invasive cancer ~1%. Diagnose by biopsy (gold standard); treat with excision, electrocautery, cryotherapy, laser, or topical 5-fluorouracil.
Verrucous carcinoma (Buschke-Löwenstein tumour, giant condyloma) — associated with HPV 6 and 11; progression to invasive cancer ~30%. It grows locally and destroys adjacent tissue by compression but does not metastasize (unlike condyloma acuminatum, which always stays superficial). Requires surgical excision — radiation is ineffective.
Carcinoma in situ (CIS):
- Erythroplasia of Queyrat — CIS of the glans or foreskin; progression ~30%.
- Bowen's disease — CIS of the penile shaft, remaining genitalia, or perineum; progression ~5%.
- Metastasis is extremely rare, and CIS is not associated with visceral malignancies.

Penile Kaposi sarcoma — associated with HHV-8; prompts evaluation for HIV/immunosuppression. Presents as a raised, painful, bleeding papule or ulcer with bluish discolouration. Four categories: classic (no known immunodeficiency, indolent), immunosuppression-related (e.g. transplant), African (young men, indolent or aggressive), and epidemic/HIV-related (AIDS). The classic and immunosuppressive forms are non-epidemic — penile-limited non-epidemic disease should be treated aggressively, as it rarely involves other organs. Management: in HIV, start/optimize HAART (often induces remission); local options include laser, cryotherapy, excision, and topical retinoids; disseminated/visceral disease needs combination chemotherapy.
Penile cutaneous horn — rare; develops over a pre-existing lesion (wart, nevus, abrasion, or malignancy) as a cornified protuberance. It may recur and show malignant change on later biopsy even when initially benign, so careful histology of the base and close follow-up are essential.
Leukoplakia.
Lichen sclerosus (see the Penis and Urethra Surgery topic).
Pseudoepitheliomatous micaceous and keratotic balanitis.

Which premalignant lesion has the highest rate of progression to invasive cancer, and how is it treated? Verrucous carcinoma (Buschke-Löwenstein tumour) and erythroplasia of Queyrat both progress at ~30%; verrucous carcinoma requires surgical excision (radiation is ineffective).
How do erythroplasia of Queyrat and Bowen's disease differ? Both are CIS — erythroplasia of Queyrat affects the glans/foreskin (progression ~30%), Bowen's disease the shaft/perineum (progression ~5%).
What finding on a penile lesion should prompt HIV testing? Kaposi sarcoma (HHV-8 associated) — investigate for HIV or other immunosuppression.