[Bilateral tumors of the testis: the role of the diagnosis of carcinoma in situ in early detection].

In a series of 540 patients with testicular germ cell tumors, the diagnosis of bilateral tumor was observed nine times. Two patients presented a simultaneous bilateral tumor and for seven others a second tumor occurred after an interval varying from 1 to 16 years. The often late discovery of the contralateral cancer sometimes requires a prolonged follow up for patients with unilateral testicular malignancy. Incidence, risk factors and therapy are discussed, in particular the anomalies in testicular migration, hypofertility, testicular atrophy and carcinoma in situ. Prevention of bilateral consecutive tumors depends on the research of carcinoma in situ thanks to testicular biopsy. A slight radiotherapy allows eradication of this tumor, whose evolution towards invading cancer is particularly high. A rigorous watch of these patients can be considered. With the absence of early detection, the treatment of the simultaneous tumor needs taking into consideration the treatment of the initial tumor. In case of a diagnosis at stage 1, observation after orchidectomy is possible without further treatment.