Sertoli cell types in the Sertoli-cell-only syndrome: relationships between Sertoli cell morphology and aetiology

Histological study of testicular biopsies from infertile men showing Sertoli-cell-only tubules due to hypogonadotropic hypogonadism, cryptorchidism, oestrogen treatment, chemotherapy or Del Castillo's syndrome, revealed four types of Sertoli cells: (1) normal adult mature cells showing an indented nucleus, grossly triangular in shape with a prominent tripartite nucleolus; (2) immature cells with round regularly outlined nuclei and immature cytoplasm; (3) dysgenetic cells showing immature nuclei and a nearly mature cytoplasm with less developed cytoplasmic organelles; and (4) involuting cells with very irregularly outlined nuclei and a mature cytoplasm containing abundant lipid droplets and residual bodies and atypical inter-Sertoli junctional specializations. Testes from men with hypogonadotropic hypogonadism showed only immature Sertoli cells; cryptorchid testes showed dysgenetic cells and occasional normal cells; and after treatment with oestrogens or chemotherapy the testes showed involuting cells and normal cells. The testes of men with Del Castillo's syndrome could be classified into three groups, according to the Sertoli cell type present: mature, dysgenetic and involuting cells. This finding suggests that Del Castillo's syndrome may be due to at least three different aetiologies.