title: Ectopic Adrenocorticotropic Hormone-Secreting Pituitary Adenomas: An Underestimated Entity.
abstract: The diagnosis of Cushing disease is based on endocrinological pa-rameters, with no single test being specific. In some patients, dynamic thin-slice sellar magnetic resonance imaging fails to detect a pituitary tumor.
  
  
  
  The purpose of this study is to investigate the role of ectopic pituitary adenoma in this situation.
  
  
  
  In a retrospective chart review, 5 patients (6%) with ectopic adenomas were identified in 83 consecutive patients undergoing transsphenoidal surgery for adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas by 1 surgeon.
  
  
  
  In all 5 patients (all female, 32-41 years of age), an exclusively extrasellar ACTH-secreting adenoma was excised. Three adenomas were located in the cavernous sinus, 1 in the sphenoid sinus, and 1 in the ethmoidal cells. Histologically, none of the tumors showed signs of aggressiveness. Three of the 5 adenomas specifically expressed somatostatin receptor 5. In 4 patients with Cushing disease, postoperative remission was obtained, with 1 recurrence after 14 months. In the patient with Nelson syndrome, ACTH decreased from >800 to <80 pg/mL. Three patients underwent previous surgery elsewhere, including 1 hypophysectomy. In this case, the ectopic adenoma (positive for somatostatin receptor 5) in the ethmoidal cells turned out to be positive on gallium 68 DOTATATE positron emission tomography/computed tomography.
  
  
  
  The incidence of primarily ectopic ACTH-secreting adenomas in this series was 6%. In cases of negative MRI findings, an ectopic ACTH-secreting adenoma should be taken into account. 68 Ga DOTATATE positron emission tomography/computed tomography may identify ectopic pituitary adenomas. Hypophysectomy should always be avoided in primary surgery for CD.
authors.affiliation: Department of Neurosurgery, Johannes Wesling Klinikum, Minden, Germany.
authors.forename: Ulrich J
authors.initials: UJ
authors.lastname: Knappe
authors.affiliation: Department of Endocrinology, Johannes Wesling Klinikum, Minden, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Jaspers
authors.affiliation: Department of Endocrinology, Johannes Wesling Klinikum, Minden, Germany.
authors.forename: Desirée
authors.initials: D
authors.lastname: Buschsieweke
authors.affiliation: Institute of Radiology, Johannes Wesling Klinikum, Minden, Germany.
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Reinbold
authors.affiliation: Department of Neurosurgery, Johannes Wesling Klinikum, Minden, Germany.
authors.forename: Ali
authors.initials: A
authors.lastname: Alomari
authors.affiliation: Institute of Neuropathology, Univers-itätskrankenhaus Eppendorf, Hamburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Saeger
authors.affiliation: Gesundheitszentrum Mar-tinshof, Giessen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Ehlenz
authors.affiliation: Endokr-inologikum Frankfurt/Main, Frankfurt, Germany.
authors.forename: W Alexander
authors.initials: WA
authors.lastname: Mann
authors.affiliation: Department of Endocrinol-ogy, Philipps University, UKGM, Marburg, Germany.
authors.forename: Peter Herbert
authors.initials: PH
authors.lastname: Kann
authors.affiliation: Department of Endocr-inology, Klinikum Bielefeld, Bielefeld, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Feldkamp
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D002426:Cavernous Sinus / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000601:surgery*; D047748:Pituitary ACTH Hypersecretion / Q000000981:diagnostic imaging / Q000601:surgery*; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Cushing disease; Ectopic Cushing syndrome; Pituitary adenoma; Pituitary surgery; Somatostatin receptor