TY - CHAP M1 - Book, Section TI - Chapter 20. Other Functional and Nonfunctional Neuroendocrine Tumors A1 - Saunders, Brian D. A1 - Doherty, Gerard M. A2 - Morita, Shane Y. A2 - Dackiw, Alan P. B. A2 - Zeiger, Martha A. Y1 - 2010 N1 - T2 - McGraw-Hill Manual: Endocrine Surgery AB - The pancreas is a retroperitoneal organ that is composed of multiple lineages of neuroendocrine cells interspersed within the larger structure of its exocrine ductal system. The neuroendocrine cells are histologically grouped into islands known as islets of Langerhaans. These islet cells are differentiated such that they each synthesize and secrete only one of six pancreatic endocrine hormones. These hormones play an integral role in the fine balance of normal physiology. Both benign and malignant neoplastic processes can affect the pancreatic neuroendocrine cells. This tumor formation may be the result of a sporadic, somatic mutation or an inherited genetic predisposition to tumorigenesis. Although some of the tumors that develop retain sufficient differentiation to elicit the specific hormone made by the cell of origin, defects are often present in the normal feedback control of hormone release. This may result in a clinically detectable syndrome of hormone excess that may be diagnostically useful before detection of symptoms related to the primary tumor mass or metastatic burden. Pancreatic neuroendocrine tumors (PNETs) are relatively rare, with approximately five cases occurring per 1 million people annually. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/11/08 UR - accesssurgery.mhmedical.com/content.aspx?aid=6163846 ER -