ENETS consensus guidelines for the management of patients with digestive neuroendocrine neoplasms: Functional pancreatic endocrine tumor syndromes. Neuroendocrinology 2012

Gastrinomas are neuroendocrine neoplasms, usually located in the duodenum or pancreas, that secrete gastrin and cause a clinical syndrome known as Zollinger-Elli-son syndrome (ZES). ZES is characterized by gastric acid hypersecretion resulting in severe peptic disease (peptic ulcer disease (PUD), gastroesophageal reflux disease (GERD)) [8–10]. In this section, ZES due to both duode-nal and pancreatic gastrinomas will be covered together because clinically they are similar [8, 10]. Specific points related to gastrinomas associated with the genetic syn-drome of Multiple Endocrine Neoplasia type 1 (MEN1) (25 % of cases) will also be mentioned [11, 12]. Insulinomas are neuroendocrine neoplasms located in the pancreas that secrete insulin, which causes a distinct syndrome characterized by symptoms due to hypoglyce