Periodic Remission in Cushing's Disease with Paradoxical Dexamethasone Response: An Expression of Periodic Hormonogenesis

Abstract

A patient with Cushing's disease due to a chromophobe adenoma was studied for 243 days before pituitary surgery and evidence for periodicity in cortisol steroid production wasfound with cycles occurring every 85.8 days (peak-to-peak length), associated with laboratory remissions and paradoxical response to dexamethasone. The autonomy of ACTH secretion was suggested by the nonresponsiveness to repeated lysine-vasopressin stimulation tests and lack of increase in urinary 170HCS following metyrapone. A distinct response of the hyperplastic glands (as demonstrated by percutaneous adrenal venography) was obtained on several B^1–24 corticotropin stimulation. The patient's hypercortisolism disappeared following removal of the chromophobe adenoma throughtransphenoidal hypophysectomy.