A pancreatic islet cell tumor is an uncommon tumor of the pancreas that arises from a cell in the pancreas, referred to as the islet cell. Normally, islet cells produce insulin and other hormones, and islet cell tumors can also produce hormones.
In the normal pancreas, cells called islet cells produce hormones that regulate a variety of bodily functions, such as blood sugar level and the production of stomach acid.
Tumors that arise from islet cells of the pancreas can also produce a variety of hormones, though some do not. Although islet cells produce many different hormones, most tumors secrete only one specific hormone that leads to specific symptoms. Pancreatic islet cell tumors can be benign or malignant (cancerous).
Islet cell tumors include insulinomas, glucagonomas, and gastrinomas (Zollinger-Ellison syndrome). A family history of multiple endocrine neoplasia, type I (MEN I) is a risk factor for the development of islet cell tumors.