Giant Sertoli cell nodule of the testis: distinction from other Sertoli cell lesions.

The case of a 33-year-old man with a clinically suspected testicular neoplasm is reported here. The radical orchidectomy specimen showed a sharply demarcated, firm, yellow-white 1-cm nodule beneath the tunica albuginea at the upper pole. Microscopical examination showed the encapsulated nodule to be composed of tubules lined by immature Sertoli cells with interspersed spermatogonia and an interwoven network of hyalinised basement membrane having foci of calcification. Immunohistochemical studies verified the fetal phenotype of the Sertoli cells and the non-neoplastic nature of the germ cell component. Except for the large size, the findings were identical to those of a Sertoli cell nodule-a typically microscopic, unencapsulated lesion commonly detected in cryptorchid testes. The term "giant Sertoli cell nodule" is used for this unique, hitherto undescribed lesion and its distinction from other Sertoli cell lesions of the testis is considered here.