NONFUNCTIONING CYSTIC NEUROENDOCRINE NEOPLASMS OF THE PANCREAS

Background. Three types (functioning solid, nonfunctioning solid, and functioning cystic) of neuroendorcine neoplasms (benign and malignant) of the pancreas have been reported. Patients. We report three patient s with nonfunctioning neuroendocrine neoplasms of the pancreas with cy stic components, a type of neoplasm not previously reported. One of th e neoplasms we report was benign; the other two were malignant. The pa tients were admitted with abdominal pain. In each case an abdominal co mputed tomography scan defined a large multicystic pancreatic mass. Re sults. In all instances, immunochemical staining was positive for neur oendocrine nature, confirming the neuroendocrine nature of the tumors. The nonfunctional nature of the neoplasms was confirmed by (1) the ab sence of clinical symptoms traditionally attributed to neuroendocrine secretagogues and (2) the lack of gastroenteropancreatic peptide serum levels. Conclusions. Two of these three cases represent another subse t of pancreatic neuroendocrine pathology: a nonfunctional cystic neopl asm. Increased clinical awareness, appropriate operation, and better i mmunohistochemical staining techniques may yield more, heretofore unre cognized, subtypes. These cases reemphasize the need for proper surgic al exploration and biopsy of all unexplained pancreatic cystic lesions , particularly if they are multicystic.