Screening for carcinoma in situ of the contralateral testis in patients with germinal testicular cancer.

Two hundred and fifty biopsy specimens from the contralateral testis in patients with unilateral germinal testicular cancer were analysed by light microscopy for carcinoma-in-situ changes. Changes were found in 13 (5.2%) patients. One-third of patients with an atrophic contralateral testis (volume less than or equal to 12 ml) and one-fifth of patients with a history of cryptorchidism had changes in the remaining testis. In the present series 85% of cases with carcinoma-in-situ changes would have been diagnosed if the one-fifth of the patients having an atrophic testis or a history of cryptorchidism or both had been screened. Since the natural course of carcinoma in situ in the contralateral testis of patients with germinal testicular cancer has not been established, the patients are being re-evaluated frequently. To date two patients with carcinoma in situ have developed a second cancer.