A Rare Cause of Hypoglycemia in Elderly Patients: Insulinoma.

Insulinoma is the most common pancreatic neuroendocrine tumor and is often solitary and benign. To make a diagnosis, high insulin levels must be demonstrated, and proinsulin and C-peptide measurements must be done. The presence of hypoglycemic measurements and symptoms in the 72-hour fasting test is diagnostic. We present a case of a 91-year-old patient with no known diagnosis of diabetes mellitus who was admitted to the emergency department due to confusion. As a result of the clinical evaluation and differential diagnosis, it was determined that her complaint was due to hypoglycemia, and she was admitted to the internal medicine service for further examination, diagnosis, and treatment.