Abstract
Insulinoma is a rare neuroendocrine tumor that causes inappropriate release of insulin, resulting in episodes of hypoglycemia. It classically present with neuroglycopenic and autonomic sympathetic symptoms. These symptoms resolve promptly following glucose administration. Demonstration of elevated C-peptide level in the presence of hypoglycemia and absence of plasma sulfonylurea is suggestive of the diagnosis. Pre-operative localization of the tumor is essential. Herein, we present the case of middle-aged man who had a 6-month history of recurrent episodes of irritability and fatigue that resolved after eating. Pancreatic insulinoma was localized by computed tomography scan. The patient underwent successful resection of the tumor, and his symptoms showed complete resolution.