title: Clinical features and management of ectopic ACTH syndrome at a single institute in Japan.
abstract: Ectopic ACTH syndrome (EAS) is a diagnostic challenge because it is often indistinguishable from Cushing's disease. We describe our series of EAS patients referred to us during 1992-2009. Among 16 cases (9 females / 7 males), with mean age of 58.4 ± 19.0yr, the ectopic source was identified in ten (proven EAS), whereas unidentified in six (occult/unknown EAS). Their salient clinical manifestations included Cushingoid feature (88%), skin pigmentation (88%), profound hypokalemia (88%), hypertension (75%), diabetes/impaired glucose tolerance (75%), hyperlipidemia (69%), and severe infection (44%). Dynamic endocrine tests revealed markedly elevated plasma ACTH levels (211 ± 116pg/mL) and cortisol levels (60.9 ± 30.1µg/dL) which showed resistance to overnight high-dose (8mg) dexamethasone suppression test in 15 (94%) and unresponsiveness to CRH stimulation in 12 (75%). No ACTH gradient during inferior petrosal sampling was noted in 13 of 15 (87%). Imaging tests by CT/MRI identified the tumors in 8 of 16 (50%), in 4 of 11 (36%) and 4 of 6 (66.7%) octreotide-responders by somatostatin receptor scintigraphy, but in only one of 9 (11.1%) by FDG-PET scan. Six cases deceased, including small cell carcinoma (2) and adenocarcinoma (1) of lung, neuroendocrine carcinoma of pancreas (1) and stomach (1), and olfactory neuroblastoma (1), whereas 4 cases survived after removal of the tumors, including bronchial carcinoid tumor (3) and thymic hyperplasia (1). Six occult/unknown EAS patients survived for 67.5 months after medical treatment with metyrapone to control hypercortisolism. Thus, various endocrine tests combined with imaging studies are required to correctly localize the tumors. Control of hypercortisolemia by metyrapone, even if tumor is unrecognized, is critical for better prognosis, and the long-term follow-up by repeated endocrine and imaging tests is mandatory.
authors.affiliation: Department of Clinical and Molecular Endocrinology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Doi
authors.forename: Toru
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Hajime
authors.initials: H
authors.lastname: Izumiyama
authors.forename: Takanobu
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hirata
mesh_terms: D000182:ACTH Syndrome, Ectopic / Q000175:diagnosis* / Q000628:therapy; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000368:Aged; D003346:Corticotropin-Releasing Hormone; D003907:Dexamethasone; D003920:Diabetes Mellitus; D003937:Diagnosis, Differential; D005260:Female; D018149:Glucose Intolerance; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006949:Hyperlipidemias; D006973:Hypertension; D007008:Hypokalemia; D007564:Japan; D008297:Male; D008797:Metyrapone / Q000627:therapeutic use; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery; D047748:Pituitary ACTH Hypersecretion; D012880:Skin Pigmentation; D014057:Tomography, X-Ray Computed
chemical_list: D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone; D008797:Metyrapone