Gastric Collision Tumor: A Rare case of an Adenocarcinoma and Carcinoid tumor

Abstract

We report a rare case of gastric collision tumor composed of well differentiated tubular adenocarcinoma and typical carcinoid in an 47year-old woman. On endoscopic examination, an invasive tumor was noted at the pyloric end of the stomach, and a pathologic examination of the biopsy specimen revealed adenocarcinoma. After total gastrectomy, a thorough histopathologic examination of the resected tumor revealed the concurrent presence of well differentiated adenocarcinoma and typical carcinoid tumor, which had a colliding pattern of tissue proliferation. The presence of either tumor individually would not be especially noteworthy, but this collision-type tumor of both histopathologic types in the stomach is, to our knowledge, is the eight case in the literature