Endocrine studies in Sertoli-cell-only syndrome.

Pituitary-gonadal endocrine functions were studied in 15 patients with Sertoli-cell-only syndrome and a comparison was made with other testicular diseases, such as Klinefelter's syndrome. Elevated levels of serum luteinizing hormone as well as follicle stimulating hormone and lowered levels of serum testosterone suggested the existence of Leydig cell failure in addition to germ cell failure. However, the degree of these endocrinological abnormalities in patients with Sertoli-cell-only syndrome was mild compared to that in patients with Klinefelter's syndrome. Reserve capacity of Leydig cells in patients with Sertoli-cell-only syndrome was considered to be preserved as suggested by the human chorionic gonadotropin stimulation test.