Gastrinomas are neuroendocrine tumors (NETs), usually located in the duodenum or pancreas, that secrete gastrin and cause a clinical syndrome known as Zollinger-Ellison syndrome (ZES). A large number of gastrinomas develop in the pancreas or duodenum, with near-equal frequency, and approximately 10% arise as primary neoplasms in lymph nodes of the pancreaticoduodenal region (gastrinoma triangle).Most gastrinomas are sporadic (75%–80%), whereas approximately 20% to 25% are associated with multiple endocrine neoplasia type 1(MEN-1). [Source: Wikipedia ]