MEN1 and pancreatic neuroendocrine tumor: Pancreatic neuroendocrine tumors have an earlier age of onset in patients with MEN1, when compared to sporadic cases (10–50 years of age vs. 50–80 years), and tend to be multiple (as opposed to single in sporadic pNETs), most commonly leading to diffuse microadenomatosis (tumors <0.5 cm), with <13% of patients developing larger tumors (>2 cm) which are often nonfunctional (5, 6, 86–88).