Leydig cell hypofunction resulting in male pseudohermaphroditism.

An 11-year-old patient with male pseudohermaphroditism presented with essentially normal-appearing female external genitalia. When examined, inguinal gonads, redundant foreskin, and some posterior labial fusion were found. Evaluation revealed basal testosterone (T) levels ranging from 65 to 107 ng/dl with slightly elevated serum gonadotropin levels (luteinizing hormone [LH]: 76 ng/ml, and follicle-stimulating hormone [FSH]: 568 ng/ml). Neither T nor its precursors increased with human chorionic gonadotropin (hCG) stimulation. However, progesterone (P), 17-hydroxyprogesterone (17-OHP), and cortisol (F) responses to adrenocorticotropic hormone (ACTH) were normal. Androgen binding and 5 alpha-reductase activity in cultured genital skin fibroblasts were normal. These data, plus the microscopic finding of a markedly reduced number of Leydig cells, strongly suggest that the male pseudohermaphroditism in this patient was due to inadequate Leydig cell function unrelated to LH receptors.