Macronodular adrenal hyperplasia with hypothalamic-pituitary-adrenal suppression by ultra-high-dose dexamethasone: regression following hypophysectomy.
Cushing's syndrome associated with macronodular adrenal hyperplasia (MAH) may present with high-dose dexamethasone (dex) nonsuppressible hypercortisolemia. This has been interpreted as suggesting a primary adrenal disorder, leading to recommendations for curative adrenalectomy in these cases. The present case of MAH demonstrates high urinary and serum cortisol levels, sufficiently suppressed only by ultra-high-dose (32 mg/day X 2 day) dex, with parallel reduction of plasma adrenocorticotrophin noted as well. Subsequent clinical cure by transsphenoidal hypophysectomy and identification of a pituitary adenoma confirmed the secondary nature of adrenal cortical hypersecretion. The conceptual evolution of macronodules and altered feedback dynamics of the hypothalamo-pituitary-adrenal axis in MAH are briefly discussed.
D000307:Adrenal Gland Diseases / Q000150:complications / Q000503:physiopathology*; D000328:Adult; D003480:Cushing Syndrome / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D003907:Dexamethasone; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006965:Hyperplasia; D007016:Hypophysectomy; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D008297:Male
D003907:Dexamethasone; D006854:Hydrocortisone