Bilateral testicular germ cell tumors: a report of 20 cases.

Of 412 patients with unilateral testicular cancer 20 (4.3 per cent) suffered a second primary germ cell tumor: 1 had a simultaneous bilateral tumor and in the remaining 19 the second tumor was diagnosed after an interval of 2 months to 32 years. Patients with clinical stages III and IV disease were found only in the group with a second tumor. In 5 patients known risk factors for the development of testicular tumors were found and in 2 prior testicular biopsies showed carcinoma in situ. Effective chemotherapy was used more often in the treatment of the second primary tumor. Of the 20 patients 18 (90 per cent) are free of disease after a mean observation of 5.7 years. A long followup of testicular cancer patients with sonographic evaluation of the remaining testis as well as periodic self-examination by the patient is required.