VIPoma and PPoma

Gastrinomas are rare tumors of the neuroendocrine system, occurring within the pancreas and duodenum. The annual incidence is estimated at 0.5 per million of the population [1]. Overproduction of gastrin by these tumors produces a sustained increase in gastric acid secretion, leading to clinical manifestations of complicated peptic ulcer disease known as the Zollinger-Ellison syndrome (ZES) [2]. Although most gastrinomas grow slowly, over 60 % are malignant and 25 % show rapid aggressive behavior [3-5]. Most commonly gastrinomas metastasize to regional lymph nodes and the liver, and it is this malignant potential which has become increasingly important since the introduction of effective me…