Ectopic growth hormone-releasing hormone secretion by a bronchial carcinoid tumor: Clinical experience following tumor resection and long-Acting octreotide therapy

Peter W. Butler, Craig S. Cochran, Maria J. Merino, Dao M. Nguyen, David S. Schrump, Phillip Gorden

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Acromegaly resulting from the ectopic secretion of growth hormone-releasing hormone (GHRH) is rare. We present a case of acromegaly secondary to proven GHRHsecretion by a bronchial carcinoid tumor in a type 1 diabetic subject and document the clinical course pre- and postresection of the tumor and of subsequent octreotide therapy. A 54-year-old Caucasian man was referred for evaluation of acromegalic symptoms and significantly increased insulin requirements. He had a history of left lung surgery 20 years prior for hemoptysis. Initial laboratory results indicated acromegaly. Fasting serum growth hormone (GH): 26.1 ng/mL (0-5 ng/mL), insulin-like growth factor 1 (IGF-1): 635 ng/mL (87-283 ng/mL), GH at 60 min post-ingestion of 75 grams of oral glucose during a glucose tolerance test: 8.3 ng/mL (normal<1 ng/mL). Pituitarymagnetic resonance imaging (MRI) revealed diffuse pituitary enlargement without adenoma. A 4.4 cm left hilar mass was noted on chest computed tomography (CT) scan. Further evaluation for a suspected GHRH-secreting neuroendocrine tumor was pursued. Plasma GHRH level was elevated: 198 pg/mL (<50 pg/mL). Octreoscan showed radiolabelled-octreotide uptake in the left lung mass and pituitary gland. Surgical resection of the lung mass was performed. Immunohistochemical study of the tumor tissue indicated a neuroendocrine tumor secreting GHRH. Postoperatively, serum GHRH, GH and IGF-1 levels fell precipitously. At 10 months, IGF-1 levels were mildly elevated and 7 months of 10 mg longacting octreotide therapy (Sandostatin® LAR®) was trialed. At 20 months, off octreotide, serum IGF-1 levels had normalized, acromegalic features were receding, and the patient's daily insulin requirements had decreased by 57%.

Original languageEnglish (US)
Pages (from-to)260-265
Number of pages6
JournalPituitary
Volume15
Issue number2
DOIs
StatePublished - Jun 1 2012
Externally publishedYes

Keywords

  • Acromegaly
  • Carcinoid
  • Ectopic acromegaly
  • Growth hormone-releasing hormone
  • Neuroendocrine tumor
  • Octreotide
  • Somatostatin analogue

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

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