RESUMEN
All pancreatic neuroendocrine tumors derive from Langerhans islet cells and have a low incidence. Half of them are functioning tumors that produce diverse hormones and occasionally cause serious clinical endocrine syndromes. They may be malignant, but they have a better survival, if compared to pancreatic ductal adenocarcinoma. Insulinoma, gastrinoma, glucagonoma, VIPoma (VIP=vasoactive intestinal peptide), somatostatinoma and ACTHoma are functioning tumors and they may also be part of Multiple Endocrine Neoplasia type I (MEN 1) syndrome and of von Hippel-Lindau disease. Diagnosis of non-functioning tumors is usually late, when they reach a big size and have even developed nodal and hepatic metastases. Nowadays, there are effective medical treatments for the medical problems secondary to excessive hormone production. For example, the hypergastrinemia typical of the Zollinger-Ellison syndrome in gastrinoma, can be adequately managed. Surgical resection is the most advisable therapy for pancreatic endocrine tumors, especially when they are small, when long time survival is better. Pre and intra operative imagenology is a great aid to locate these tumors. There are several surgical alternatives, according to the tumor size and location within the pancreas. Furthermore, palliative therapy can be used in disseminated disease. Treatment success is the result of a multidisciplinary medical team work of endocrinologists, surgeons, gastroenterologists, pathologists and geneticists (Rev MÚd Chile 2004; 132: 627-34).