The neuroendocrine tumors of the ileum

Abstract

Neuroendocrine tumors arise from the diffuse neuroendocrine system and secrete several peptides and bioactive amines (serotonin, histamine, dopamine, norepinephrine, corticotropin, calcitonin, bradykinin, kalikrein, gastrin, cholecystokinin, prostaglandins). The most common occurrence site of neuroendocrine tumors is the ileum. The symptoms of small bowel carcinoids are represented by intermittent intestinal obstruction and carcinoid syndrome. Presence of the carcinoid syndrome usually indicates hepatic or retroperitoneal metastases. The typical carcinoid syndrome is characterized by flushing, diarrhea, nonspecific abdominal pain and bronchospasm. The diagnosis of small bowel tumors is often difficult due to their rarity and the nonspecific and variable nature of the presenting signs and symptoms. The most useful initial diagnostic test for the carcinoid syndrome is to measure 24-hour urinary excretion of 5-hydroxyindolacetic acid (5 HIAA), which is the end product of serotonin metabolism. Capsule endoscopy is a more recent diagnostic tool. Surgery is the radical form of curative therapy for carcinoid tumors. Numerous therapies are available for palliation including surgery, pharmacologic therapy, interventional radiologic therapy, embolization and chemoembolization of hepatic metastases, immunotherapy (Interferon alfa) and chemotherapy. We carefully reviewed the available literature on this topic before beginning our study. © 2008 Versita Warsaw and Springer-Verlag.