Thursday, September 25, 2008

Penis: Malignant tumours

Squamous cell carcinoma:
The frequency of squamous cell carcinoma shows a marked geographic variation, with the highest incidence in Asian countries, Africa, and Central America. The variation in frequency has been associated with personal, social, and religious practices, including personal hygiene and the practice of circumcision. In USA it accounts for about 1% of cancers in men between the ages 40 and 70 years. Carcinoma of the penis is extremely rare in Jews and Moslems.
Potential causes are carcinogens within smegma accumulating under the foreskin and HPV types 16 and 18 infection.
Grossly, it presents as epithelial thickening on the glans or inner surface of the prepuce near the coronal sulcus, progressing to ulceroinfiltrative or exophytic growth eroding the penile tip, shaft, or both.
Microscopically, it is identical to squamous cell carcinomas involving other cutaneous sites.
Clinically, it is characterized by slow growth with metastases to regional (inguinal and iliac) lymph nodes; distant metastases are common. This progression can be expected within 2 years of the initial diagnosis.
The 5-year survival rate is 66% for lesions confined to penis and 27% with regional node involvement.
Verrucous carcinomas:
Verrcous carcinomas, also called giant condyloma or Buschke-Lowenstein tumor, is an uncommon, well-differentiated form of squamous cell carcinoma with low malignant potential. This is seen with greater frequency in the larynx. The carcinoma cells show minimal atypia. Large penile carcinomas cause complete destruction of penis.