Sertoli cell only syndrome (SECOS): lessons from case studies.

Between June 85 and December 87, 69 testicular biopsies were submitted for histopathological examination during investigation of infertility; ten (14%) patients had a Sertoli cell only syndrome. The history, clinical features, and hormonal profiles were analyzed in an attempt to categorize these patients on aetiological basis. Two followed treatment of malignancy--one by radiation for testicular cancer and one by cyclophosphamide for a lymphoma. One had unilateral cryptorchidism. Mumps was etiological factor in one patient. FSH levels determined in 6 patients were elevated in all suggesting a possible dependence of (sick) Sertoli cells on spermatogenic cells for production of inhibin. Alternative explanations include changes in sertoli cell enzymes or FSH receptors. Testosterone levels are in the low normal range suggesting that Leydig cells may also be affected by the etiological factor producing the syndrome. Two patients who had earlier received a higher Johansen score were found to have a sertoli cell only syndrome on expert review of testicular biopsies. It is suggested that the condition is more common than hitherto reported and is often confused with maturation arrest. Testicular histopathology should be done by specialists in testicular pathology.