RT Journal A1 Stabile BE T1 WHen pnets bust out of their shells JF Archives of Surgery JO Archives of Surgery YR 2012 FD September 1 VO 147 IS 9 SP 828 OP 828 DO 10.1001/archsurg.2012.1281 UL http://dx.doi.org/10.1001/archsurg.2012.1281 AB Analyzing selected population data for the purpose of determining the natural history of disease is nearly always difficult. This difficulty is exemplified by the study by Krampitz and colleagues,1 which addresses the importance of lymph node metastases on the clinical outcomes of patients with pancreatic neuroendocrine tumors (pNETs). The results presented are useful in that they strongly corroborate previous findings that pNET liver metastases are relatively indolent but almost always ultimately lead to patient demise and that hormonally functional (except for insulinoma) and nonfunctional pNETs have similar biological behaviors, including metastatic potential. Also important was the finding that duodenal gastrinoma primary tumors are less aggressive than their pancreatic counterparts, although any difference in the biologic behaviors of pancreatic primaries within vs outside the gastrinoma (Passaro) triangle was not specifically addressed. Unfortunately, the findings presented are derived from 2 different institutional databases encompassing different periods that contain an atypical preponderance of gastrinomas and a paucity of insulinomas. The result is a maldistribution that does not legitimately represent the normal spectrum of pNETs and thus renders the demographics, array of symptoms, frequencies of multiple endocrine neoplasia 1 and malignant tumors, and anatomical distributions of primary and metastatic tumors nonrepresentative and somewhat misleading.