[Undescended testis cancer: report of two cases--review of the literature of 179 cases in Japan].

Recently, we experienced two cases of testicular tumor in patients with cryptorchidism. Case 1: A 35-year-old man was admitted because of right inguinal mass. He had a tumor of right undescended testis and underwent right orchiectomy. Case 2: A 45-year-old man, who was pointed out to have bilateral cryptorchidism was admitted because of right groin mass. He underwent right orchiectomy and left orchiopexy. Histological examination of two cases were seminoma. Testicular tumor in undescended testis was made with 179 reported cases from the Japanese literature.