Papillary adenocarcinoma of the male urethra. Case report and review of the literature.

Mucinous papillary adenocarcinoma of the bulbous urethra developed in a 40-year-old man with congenital stricture. The tumor appeared as a localized polypoid exophytic mass without evidence of submucosal invasion (Stage 0). The tumor was determined not to be of prostatic origin clinically and by absence of immunoperoxidase staining for prostatic acid phosphatase, prostate specific antigen, and carcinoembryonic antigen. Surgical resection of the urethra revealed extensive squamous and glandular metaplasia (urethritis glandularis) in association with the neoplasm. The mucosa displayed a spectrum of epithelial changes varying from dysplasia to carcinoma in situ, in confirmation of the urethral origin of the tumor. These observations emphasize the close association of metaplastic proliferative lesions and malignancy in the lower urinary tract.