Rare and unusual tumors of the genitourinary tract.

The entity of small cell undifferentiated carcinoma of the urinary tract is clearly recognized, though treatment still poses considerable difficulties. Small cell undifferentiated carcinoma may lead to systemic symptoms by hormone production, even in patients with localized tumors. The survival rates of adults with Wilms' tumor approach only 50% of those seen in children. Cisplatin may be effective in relapsing patients. Cancer of the female urethra should be treated by combined surgery and radiotherapy. One should differentiate between urachal and nonurachal adenocarcinoma. DNA ploidy seems to be an important prognostic parameter in adenocarcinoma of the bladder. After orchiectomy, adjuvant chemotherapy is recommended even in testis-confined malignant lymphoma. Organ-preserving surgery and radiotherapy should be used in malignant lymphoma of the bladder. Patients with uncommon urologic tumors should be treated at larger cancer centers. Alternatively, the clinician should at least enter relevant information on patients seen with these malignancies into collective databases. This review summarizes the clinical aspects of rare and unusual tumors of the genitourinary tract in adults.