Insulinoma

  • Definition

    An insulinoma is a tumor in the pancreas that produces too much insulin.


    Alternative Names

    Insuloma; Islet cell adenoma


    Causes, incidence, and risk factors

    The pancreas is an organ in the abdomen that makes several enzymes and hormones, including the hormone insulin. Insulin's job is to reduce the level of sugar (glucose) in the blood by helping it move into cells.

    Most of the time when your blood sugar level drops too low, the pancreas stops making insulin until your blood sugar returns to normal. Tumors of the pancreas that produce too much insulin are called insulinomas. Insulinomas keep making insulin, even when your blood sugar drops too low.

    High blood insulin levels cause low blood sugar levels (hypoglycemia). Hypoglycemia may be mild, leading to symptoms such as anxiety and hunger. Or it can be severe, leading to seizures, coma, and even death.

    Insulinomas are rare tumors. They usually occur as single, small tumors in adults.

    These tumors are very rare in children. Most children with high blood insulin levels have many areas of overactive insulin-releasing cells in the pancreas, instead of a single tumor.

    Taking medications that cause too much insulin in the blood, either accidentally or on purpose, is about as common as insulinoma.

    More than 90% of insulinomas are non-cancerous (benign) tumors. People with the genetic syndrome called multiple endocrine neoplasia type I are at risk for insulinomas and other endocrine tumors.