A pancreatic islet cell tumor is a tumor that develops in the pancreas from a type of cell called an islet cell. It is a rare tumor of the pancreas that starts from the islet cell.

Islet cells manufacture and release hormones, such as insulin and glucagon, into the bloodstream. An islet cell tumor can be benign (noncancerous) or malignant (cancerous).

Like pancreatic adenocarcinoma, islet cell tumors may cause abdominal pain, weight loss, nausea, and vomiting. Islet cell tumor is an older name for pancreatic neuroendocrine tumor (PNET), a type tumor of the pancreas.

Hormones released by an islet cell tumor can also cause symptoms that include: Insulinomas (excess insulin), Glucagonomas (excess glucagon), Gastrinomas (excess gastrin), Somatostatinomas (excess somatostatin), VIPomas (excess vasoactive intestinal peptide).