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Insulinoma

Last updated: October 11, 2020

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Insulinomas are predominantly benign, pancreatic islet beta-cell tumors associated with increased insulin production. While most insulinomas are sporadic, some are associated with multiple endocrine neoplasias (e.g., parathyroid tumors, pituitary adenomas, gastrinomas). Insulinomas present clinically with recurrent attacks of hypoglycemic symptoms that subside after glucose intake. The diagnosis is established by demonstrating inappropriately elevated serum insulin following a fasting test. Insulinomas are differentiated from other causes of hyperinsulinemia (e.g., exogenous insulin administration) by the presence of elevated levels of proinsulin and C-peptide. The treatment of choice is surgical enucleation of the insulinoma. In inoperable cases and patients with persistent hypoglycemic attacks, diazoxide can be used to decrease insulin secretion.

  • Sex: >
  • Age range: ∼30–60 years
  • Incidence: ∼ 4 cases/1,000,000 persons per year [1]

Epidemiological data refers to the US, unless otherwise specified.

References:[4][5]

References:[4][5]

Elevated C-peptide and proinsulin levels may also be the result of sulfonylurea use! This can be ruled out by screening serum samples for sulfonylureas.

References:[4][6][7]

References:[3][7][8]

  1. Okabayashi T. Diagnosis and management of insulinoma. World Journal of Gastroenterology. 2013; 19 (6): p.829. doi: 10.3748/wjg.v19.i6.829 . | Open in Read by QxMD
  2. Grant CS. Insulinoma. Best Practice & Research Clinical Gastroenterology. 2005; 19 (5): p.783-798. doi: 10.1016/j.bpg.2005.05.008 . | Open in Read by QxMD
  3. Jensen RT, Cadiot G, Brandi ML, et al. ENETS Consensus Guidelines for the Management of Patients with Digestive Neuroendocrine Neoplasms: Functional Pancreatic Endocrine Tumor Syndromes. Neuroendocrinology. 2012; 95 (2): p.98-119. doi: 10.1159/000335591 . | Open in Read by QxMD
  4. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015
  5. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Elsevier Saunders ; 2014
  6. Insulinoma. https://radiopaedia.org/articles/insulinoma. Updated: February 12, 2017. Accessed: February 12, 2017.
  7. INSULINOMA. http://www.surgery.usc.edu/divisions/tumor/pancreasdiseases/web%20pages/Endocrine%20tumors/pancreatic%20tumors/insulinoma.html. Updated: February 12, 2012. Accessed: February 12, 2017.
  8. Ashcroft FM. ATP-sensitive potassium channelopathies: focus on insulin secretion. J Clin Invest. 2005; 115 (8): p.2047-2058. doi: 10.1172/jci25495 . | Open in Read by QxMD
  9. Herold G. Internal Medicine. Herold G ; 2014
  10. Endocrine tumours of the pancreas. https://radiopaedia.org/articles/endocrine-tumours-of-the-pancreas. Updated: February 12, 2017. Accessed: February 12, 2017.
  11. F John Service. Insulinoma. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/insulinoma.Last updated: June 22, 2016. Accessed: February 12, 2017.
  12. Service FJ, Vella A. Factitious hypoglycemia. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/factitious-hypoglycemia.Last updated: October 20, 2016. Accessed: February 12, 2017.
  13. Eun Byul Kwon, Hwal Rim Jeong, Young Seok Shim, Hae Sang Lee, and Jin Soon Hwang. Multiple Endocrine Neoplasia Type 1 Presenting as Hypoglycemia due to Insulinoma. Journal of Korean Medical Science.. 2016 .