Range of tumours

The range of tumours affecting the penis is shown in Table 21.1.

Incidence and epidemiology

Penile cancer is relatively uncommon with around 350 cases annually in the UK, although in Asia, Africa and South America (e.g. Uganda, Brazil) the disease is more common. The peak incidence is in men over age 70 but a substantial number of cases occur in much younger men.

Risk factors and aetiology

Penile cancer appears to be less consistently associated with HPV than is cervical carcinoma. Most studies have only identified HPV subtypes 16 and 18 in around 50% of cases of classic squamous cell tumours, although there is a more consistent association with carcinoma in situ and the verrucous variant of squamous cell carcinoma (Dillner et al., 2000). Circumcision at birth reduces the risk considerably, and this leads to a theory that carcinoma of the penis is related to poor hygiene, possibly to the accumulation of smegma. Phimosis is thought to increase the risk, and also makes early detection much more difficult; tumours are more likely to present late.

Pathology

A number of premalignant lesions are recognised. Balanitis xerotica obliterans is the penile equivalent of lichen planus and is associated with a small risk of invasive cancer. Intraepithelial carcinoma presents in a variety of shapes, from nodules to erythematous plaques. It is designated erythroplasia of Queyrat if it appears on the glans or prepuce, or Bowen's disease if it involves the skin.