Bilateral testicular germ cell malignancy.

The other testicle was involved in 6 of 235 patients (2.69 per cent) with a history of testicular germ cell tumor. It occurred more often following seminoma (4 of 113, 3.5 per cent cases). The mean age at occurrence of the first tumor (twenty-five years) was earlier than expected, and the mean interval between tumors was 8.8 years. Accurate clinical staging of second tumors is impeded by alteration in the routes of metastatic dissemination, and treatment options are limited by previous therapy for the first tumor.