Insulinoma is a rare neuroendocrine tumor that overproduces insulin from the pancreatic beta cells. Typically small and benign, usually less than 2 cm. Annual incidence is estimated at 1-4 per million population. Usually diagnosed in individuals aged 40-60, with 5-10% cases associated with MEN1 syndrome. Clinical symptoms include hypoglycemia and Whipple triad: low blood sugar, hypoglycemic symptoms, and relief with glucose. Diagnosis often involves a 72-hour fasting test, elevated insulin, C-peptide, and proinsulin levels, as well as imaging for localization. Treatment is surgical resection