[A case of bilateral testicular tumor of germ cell origin]

A 28-year-old man visited our clinic with a complaint of painless swelling of left scrotal contents. An initial right semicastration for embryonal carcinoma and seminoma had been performed 10 years earlier. Left semicastration was performed, and its histopathological finding was pure seminoma. A total of 96 cases of bilateral testicular tumors of germ cell origin reported in Japan are summarized and discussed concerning incidence, age, histology, interval, prognosis and mechanism of the tumorigenesis.