Cancer Gastrointestinal Carcinoid Tumors Gastrointestinal Carcinoid Tumors About Gastrointestinal Carcinoid Tumors Gastrointestinal carcinoid tumors most often begin in neuroendocrine cells in the gastrointestinal (GI) tract, primarily in the appendix, Read More 2 500 June 19, 2018 0 2 500