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Acromegaly with concurrent ACTH secretion: Cushing syndrome masked by acromegaly

Friday, November 08, 2013 — Poster Session III

10:00 a.m. – 12:00 p.m.

FAES Academic Center (Upper-Level Terrace)




  • C. Lyssikatos
  • M. Quezado
  • C. A. Stratakis


Acromegaly with corticotrophin co-secretion is a rare entity; Cushing syndrome manifestations are often masked by the excess growth hormone (GH) production. A 34-year-old male who was in normal state of health until the age of 29, at which time he noticed an increase in the size of his hands and feet, headaches and facial feature coarseness. Body habitus was that of a patient with acromegaly, lacking any of Cushing syndrome stigmata. GH was 1.91 ng/mL (0.0-0.8); pituitary MRI revealed an 18 x 15 mm pituitary adenoma. Post transphenoidal resection (TSS) of his pituitary adenoma, his IGF-1 remained elevated at 756 ng/mL (107-310) and repeated MRI, was consistent with a 10 x 12 mm adenoma, and IGF-1 of 917 ng/ml (115-307). He underwent a second TSS which cured his acromegaly. His pm and am cortisol measured at 15.3 mcg/dL (5.0-25.0) and 14.9 mcg/dL respectively, prior to his cure from acromegaly but by post op day17, midnight and morning cortisols and ACTH were <1.0 mcg/dL(5.0-25.0) and <5.0 pg/ml (0.0-46.0) respectively and he was started on replacement glucocorticoids. Histology confirmed a tumor whose cells stained for GH and ACTH. ACTH co-secretion by a mammo-somatotroph pituitary tumor can be clinically significant but phenotypically unidentifiable.

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