Several tumors can arise within the small bowel, both malignant (adenocarcinomas, neuroendocrine tumors, lymphomas, and sarcomas) and benign (adenomas, leiomyomas, lipomas). Epidemiology, clinical manifestations, and specific tumor types will be reviewed here. Diagnosis, staging, and management of small bowel tumors are discussed separately. Enteroclysis (sometimes CT enteroclysis) is probably the most common study for mass lesions of the small bowel. Push endoscopy of the small bowel with an enteroscope may be used to visualize and biopsy tumors. Video capsule endoscopy can help identify small-bowel lesions, particularly bleeding sites; a swallowed capsule transmits 2 images/sec to an external recorder. Enlarge Gastrointestinal carcinoid tumors form in the lining of the gastrointestinal tract, most often in the appendix, small intestine, or rectum.. Gastrointestinal carcinoid tumors form from a certain type of neuroendocrine cell (a type of cell that is like a nerve cell and a hormone-making cell).These cells are scattered throughout the chest and abdomen but most are found in the GI tract. Neuroendocrine tumors in small and large intestine Jejunal, ileal, cecal and proximal colon NETs are usually well-differentiated and when metastatic, associated with the carcinoid syndrome. The pancreas has two functional components. tumors arise from the endocrine component of the pancreas and these endocrine tumors are called "pancreatic neuroendocrine tumors," or "islet cell tumors" for short. The duodenum then leads to the other parts of the small bowel, the jejunum and After someone is diagnosed with a gastrointestinal (GI) carcinoid tumor, doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of cancer describes how much cancer is in the body. It helps determine how serious the cancer is and how best to Each year, more than 55,000 people in the United States—most over the age of 60—will be diagnosed w