Presence of a Gs alpha mutation in an adrenal tumor expressing LH/hCG receptors and clinically associated with Cushing's syndrome

We describe the case of a patient with Cushing's syndrome due to a function ing adrenal adenoma. There was a pronounced increase in serum and urinary c ortisol after administration of human chorionic gonadotropin. Immunocytoche mistry revealed positive immunostaining for LH/hCG receptors. Molecular ana lysis documented the presence of a gsp mutation at codon 201 (CGT to TGT). The existence of this type of hCG-responsive adrenal tumor may help explain the higher prevalence of cortisol-secreting adrenal tumors versus pituitar y-dependent disease in pregnant women with Cushing's syndrome as well as so me reported cares of remission following delivery.