Penile intraepithelial neoplasia

What is penile intraepithelial neoplasia?

Penile intraepithelial neoplasia is a rare pre-cancerous disease of the outer skin layer (epidermis) of the penis. It is also called Erythroplasia of Queyrat, Bowen disease of the penis, in-situ squamous cell carcinoma of the penis or P.I.N. Lesions usually appear on the glans or inner aspect of the foreskin and are almost always found in uncircumcised men. If left untreated, 10-30% of cases develop into invasive squamous cell carcinoma (cancer) of the penis.

Who is at risk of penile intraepithelial neoplasia and what causes it?

Uncircumcised males over 50 years of age are most at risk of getting penile intraepithelial neoplasia, although it may rarely occur in younger men.

Penile intraepithelial neoplasia is associated with:

• Chronic infection with human papilloma virus (HPV), the cause of genital warts
• Chronic skin disease especially lichen sclerosus & lichen planus
• Irritation by urine, friction or injury to the penile area
• Smoking
• Immune suppression by medications or disease

What are the signs and symptoms of penile intraepithelial neoplasia?

Lesions are single or multiple small red plaques on the glans or inner aspect of the foreskin. They may have a smooth, velvety, scaly or warty surface. The following signs and symptoms may occur:

• Redness and inflammation
• Itching
• Crusting or scaling
• Pain
• Ulcers
• Bleeding
• In the late stages, discharge from penis, difficulty pulling back foreskin or difficulty passing urine

Images of penile intraepithelial neoplasia

What is the treatment for penile intraepithelial neoplasia?

Skin biopsy should be performed to confirm the diagnosis, as it may resemble other forms of chronic balanitis. Biopsy is also essential to rule out invasive squamous cell carcinoma, which requires more aggressive treatment.

It is important to maintain good genital hygiene. Penile intraepithelial neoplasia can be treated in several different ways.

• 5-fluorouracil cream
• Imiquimod cream
• Cryotherapy
• Curettage & cautery
• Laser vaporisation
• Photodynamic therapy
• Radiotherapy
• Excision
• Interferon alpha

Mohs' micrographic surgery appears to be highly effective and the surgical treatment of choice in severe or recurrent cases of penile intraepithelial neoplasia.

The disease recurs in 3-10% of patients, so close follow-up is necessary to ensure a complete cure.

Partners of patients with penile intraepithelial neoplasia should be screened for other forms of intraepithelial neoplasia caused by human papilloma virus in the genital area (cervical, vulvar and anal cancer).