Abstract
Neuroendocrine tumors (NEN) are a type of heterogenous, slow-growing tumors, that only in about half of the cases can be found in the gastrointestinal tract. Half of these is in the small intestine. The ampullary NENs are rare, accounting for less than 1% of gastroenteropancreatic NENs. Gastrointestinal stromal tumors (GIST) are a more common type of tumors of the gastrointestinal tract that consist of pacemaker cells. The occurrence of both tumors simultaneously is rare, but in patients with neurofibromatosis type 1, the co-existence of NEN and GIST is more often. Here we report a case of simultaneous occurrence of a well-differentiated NEN and a GIST in a patient without neurofibromatosis. Also, we provide a short review of the current knowledge and treatment strategies regarding these tumors.