Synchronous and metachronous bilateral tumors of the testis: a single institution experience of 11 cases and review of the literature

Bilateral testicular tumors represent a very rare event and account for 2.7% of all testicular neoplasms. 15% of bilateral testicular tumors occurs simultaneously in both testicles, but in 85% of cases the second neoplasia appears in the remaining testicles of patients affected by unilateral testicular tumor after a very variable period of time. The aim of this work was to value our experience on 11 cases of bilateral testis tumors: six arised simultaneously in both gonads (five germ cell tumors and one Leydig cell tumor) and five with metachronous appearance (all germ cell tumors). A comprehensive valuation has been made considering other cases reported in literature until 1996, in order to identify predisposing conditions to bilateral disease. Examining separately synchronous and metachronous neoplasms, as far as we know, only 218 cases of simultaneous bilateral testicular tumors are reported in literature, and most of them are pure seminomas; however, after 1988 this result has been...