title: A patient with recurrent hypercortisolism after removal of an ACTH-secreting pituitary adenoma due to an adrenal macronodule.
abstract: A 41-yr-old female was referred for signs and symptoms of Cushing's syndrome. Cortisol was not suppressed by 1 mg dexamethasone (0.41 micromol/l). Midnight cortisol and ACTH were 0.44 micromol/l and 18 pmol/l, respectively. Urinary cortisol excretion was 250 nmol/24 h (normal between 30 and 150 nmol/24 h). A magnetic resonance imaging (MRI) revealed a pituitary lesion of 7 mm. ACTH and cortisol levels were unaltered by administration of human CRH and high-dose dexamethasone. Inferior sinus petrosus sampling showed CRH-stimulated ACTH levels of 128.4 (left sinus) vs a peripheral level of 19.2 pmol/l, indicating Cushing's disease. After 4 months of pre-treatment with metyrapone and dexamethasone, endoscopic transsphenoidal resection of an ACTH-positive pituitary adenoma was performed. ACTH levels decreased to 2.6 pmol/l and fasting cortisol was 0.35 micromol/l. Despite clinical regression of Cushing's syndrome and normalization of urinary cortisol, cortisol was not suppressed by 1 mg dexamethasone (0.30 micromol/l). Ten months post-operatively, signs and symptoms of Cushing's syndrome reoccurred. A high dose dexamethasone test according to Liddle resulted in undetectable ACTH, but no suppression of cortisol levels, pointing towards adrenal-dependent Cushing's syndrome. Computed tomography (CT)-scanning showed a left-sided adrenal macronodule. Laparoscopic left adrenalectomy revealed a cortical macronodule (3.5 cm) surrounded by micronodular hyperplasia. Fasting cortisol had decreased to 0.02 micromol/l. Glucocorticoid suppletion was started and tapered over 12 months. Symptoms and signs of hypercortisolism gradually disappeared. This case illustrates, that longstanding ACTH stimulation by a pituitary adenoma can induce unilateral macronodular adrenal hyperplasia with autonomous cortisol production.
authors.affiliation: Department of Endocrinology, Radboud University, Nijmegen Medical Center, PO box 9101, 6500 HB Nijmegen, The Netherlands. h.timmers@endo.umcn.nl
authors.forename: H J L M
authors.initials: HJ
authors.lastname: Timmers
authors.forename: E M
authors.initials: EM
authors.lastname: van Ginneken
authors.forename: P
authors.initials: P
authors.lastname: Wesseling
authors.forename: C G J
authors.initials: CG
authors.lastname: Sweep
authors.forename: A R M M
authors.initials: AR
authors.lastname: Hermus
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000378:metabolism / Q000601:surgery*; D000236:Adenoma / Q000378:metabolism / Q000601:surgery*; D000311:Adrenal Glands / Q000378:metabolism* / Q000473:pathology*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D003480:Cushing Syndrome / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006965:Hyperplasia / Q000150:complications / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D047748:Pituitary ACTH Hypersecretion / Q000150:complications / Q000378:metabolism / Q000473:pathology; D012008:Recurrence
chemical_list: D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone