Insulinoma
Overview
Plain-Language Overview
Insulinoma is a rare tumor that forms in the pancreas, an organ involved in blood sugar regulation. This tumor produces too much insulin, a hormone that lowers blood sugar levels. Because of this excess insulin, people with insulinoma often experience episodes of low blood sugar (hypoglycemia), which can cause symptoms like sweating, confusion, weakness, and even loss of consciousness. The condition affects the body's ability to maintain normal blood sugar, which is critical for brain function and overall energy. Diagnosis usually involves blood tests and imaging studies to find the tumor. Treatment often requires surgery to remove the tumor. Managing insulinoma is important to prevent dangerous drops in blood sugar.
Clinical Definition
Insulinoma is a rare, usually benign pancreatic neuroendocrine tumor arising from the beta cells of the islets of Langerhans. It causes inappropriate and autonomous secretion of insulin independent of blood glucose levels, leading to recurrent episodes of hypoglycemia. The hallmark clinical presentation includes Whipple’s triad: symptoms of hypoglycemia, documented low plasma glucose, and relief of symptoms after glucose administration. Most insulinomas are solitary and less than 2 cm in size, with a small percentage associated with multiple endocrine neoplasia type 1 (MEN1) syndrome. The excessive insulin secretion results in suppressed levels of C-peptide and proinsulin during hypoglycemia. The condition is significant due to the risk of severe neuroglycopenic symptoms and potential for malignant transformation in rare cases.