Is biopsy of the contralateral testis necessary in patients with germ cell tumors?

Purpose: Carcinoma in situ is present in the contralateral testis in up to 5% of patients with a primary germ cell tumor and will progress in the majority of cases to a second primary invasive cancer. We address the question of whether the other testis should be biopsied in patients with testis tumors. Materials and Methods: The literature on carcinoma in situ of the testis from 1972 to the present was critically evaluated in an attempt to address the issue of carcinoma in situ in the opposite testis. Results: Carcinoma in situ of the opposite testis in patients with a primary germ cell tumor is easily diagnosed by biopsy and cured by orchiectomy or radiation. The problem is that biopsy is unnecessary in the majority of patients, and treatment of carcinoma in situ may have undesirable physical and emotional consequences. The rare patient who has an asynchronous second primary cancer can be cured with current treatment regimens. Conclusions: We do not advocate nor does the literature support routine biopsy of the opposite testis in patients with unilateral testis tumor. Patient education and close followup are rational alternatives to intervention in all cases to diagnose a small subset who are risk for bilateral tumors.