- Last Update On : 2013-01-20
Insulin is a hormone secreted by the islet cells of the pancreas that regulates carbohydrate metabolism. Measurement of plasma insulin levels is helpful in the diagnosis of insulinoma. Eighty percent of patients have a single benign tumor, usually <2-cm in diameter, located about equally in the head, body or tail of the pancreas. About 10% of patients have multiple tumors associated with multiple endocrine neoplasia type 1 and the remaining 10% have metastatic malignant insulinoma.
Patients with insulinomas usually present with fasting hypoglycemia, but occasionally may present with postprandial hypoglycemia.The diagnosis depends on demonstrating elevated serum insulin and C peptide levels when the patient has symptoms of hypoglycemia and plasma glucose is low. One third of patients with insulinoma have an insulin level within the normal range, so it must be shown that the insulin level is high for the patient’s glucose level. Inappropriate elevation of insulin can occu