Fine structure of Sertoli and Leydig cells in azoospermic human testis

Testicular biopsy specimens taken from 7 patients, 31 to 41 yr old, with azoospermia were studied by electon microscopy. The patients displayed well-developed secondary sex characteristics, normal endocrine functions (determined by circulating and urinary gonadotropin levels), and normal plasma testosterone and T₄ levels. It was clear that the infertility was directly related to a primary testicular defect. The possibility was considered of a relation between the annulate lamellae in the Sertoli cells and the azoospermia. In the Leydig cells, intranuclear and intracytoplasmic paracrystalline inclusions were observed and a relation with the Reinke crystalloids is considered.