Gastrointestinal neuroendocrine tumors are cancers that begin in neuroendocrine cells (a type of cell that is like a nerve cell and a hormone-making cell) that line the gastrointestinal tract. 
Gastrointestinal neuroendocrine tumors are cancers that begin in neuroendocrine cells (a type of cell that is like a nerve cell and a hormone-making cell) that line the gastrointestinal tract. 