title: Ectopic adrenocorticotropin syndrome exhibiting paradoxical adrenocorticotropin responsiveness to gonadotropin-releasing hormone.
abstract: In a 37-year-old man who had Cushing's syndrome, investigations, including overnight dexamethasone suppression test, corticotropin-releasing hormone (CRH) test, pituitary MRI and inferior petrosal sinus sampling suggested the presence of ectopic adrenocorticotropin (ACTH) production. Interestingly, gonadotropin-releasing hormone (GnRH) increased plasma ACTH from 73 pg/ml to 708 pg/ml at 15 min. Furthermore, desmopressin also increased plasma ACTH whereas CRH and thyrotropin-releasing hormone (TRH) had no effect. Such paradoxical responses of plasma ACTH were observed repeatedly. A thoracic CT scan revealed a right anterior mediastinal mass, which was surgically resected. Histological and immunohistochemical examination confirmed that the tumor was an ACTH-producing carcinoid. ACTH and cortisol decreased immediately following surgery. Neither desmopressin nor GnRH administration resulted in elevation of plasma ACTH while ACTH-responsiveness to dexamethasone and CRH was restored. To our knowledge, this is the first report documenting GnRH responsiveness in ectopic ACTH syndrome.
authors.affiliation: Department of Medicine, Institute of Clinical Endocrinology, Tokyo Women's Medical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ujihara
authors.forename: T
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: R
authors.initials: R
authors.lastname: Cho
authors.forename: Y
authors.initials: Y
authors.lastname: Totsuka
authors.forename: T
authors.initials: T
authors.lastname: Imaki
authors.forename: K
authors.initials: K
authors.lastname: Nomura
authors.forename: T
authors.initials: T
authors.lastname: Nishikawa
authors.forename: K
authors.initials: K
authors.lastname: Takano
mesh_terms: D000182:ACTH Syndrome, Ectopic / Q000503:physiopathology*; D000324:Adrenocorticotropic Hormone / Q000032:analysis / Q000096:biosynthesis / Q000097:blood*; D000328:Adult; D002276:Carcinoid Tumor / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery; D003346:Corticotropin-Releasing Hormone; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D003907:Dexamethasone; D005938:Glucocorticoids; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006651:Histocytochemistry; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008482:Mediastinum; D013973:Thyrotropin-Releasing Hormone; D014057:Tomography, X-Ray Computed
chemical_list: D005938:Glucocorticoids; D007987:Gonadotropin-Releasing Hormone; D013973:Thyrotropin-Releasing Hormone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003894:Deamino Arginine Vasopressin