Clinical features of pancreatic neuroendocrine tumors.

Pancreatic neuroendocrine tumors (PNETs), also known as islet cell tumors, are rare neoplasms that arise in the endocrine tissues of the pancreas. Most of pancreatic NETs (50-75%) are nonfunctioning (not associated with a hormonal clinical syndrome); however, in up to one third they can secrete a variety of peptide hormones, including insulin, gastrin, glucagon, vasoactive intestinal peptide, somatostatin etc., resulting in rare but unique clinical syndromes. In this article, the clinical features of the different types of PNETs will be reviewed. Other aspects of the management of these tumors (surgery, treatment of advanced disease, tumor localization) are not dealt with here, as they are covered by other papers in this volume.