Last updated: July 13, 2021

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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.



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.



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