A case of simultaneous bilateral germ cell tumors arising from cryptorchid testes.

We report a rare case of simultaneous bilateral testicular germ cell tumors arising from uncorrected cryptorchid testes. Each side had a different histological type, which consisted of pure high grade seminoma on the left side, and teratocarcinoma with choriocarcinoma and yolk sac tumor elements in addition to seminoma on the right side. Patients with cryptorchidism are known to have a higher risk of germ cell tumors. Genetic factors also may have a role in the oncogenesis in our patient, since his older brother had had a seminoma in the left cryptorchid testis previously. Both patients had the HLA-Aw24 antigen. The characteristics of familial testicular tumors are discussed.