Abstract
A 73-year-old man was seen in our hospital because of exacerbation of wobbling gait. Blood examination showed anemia and slight increases in CEA and CA19-9 levels. Upper gastrointestinal endoscopy showed adjoining type-3 and type-2 tumors at the gastric lesser curvature. Biopsy was performed from both lesions, which were diagnosed as moderately differentiated adenocarcinomas. CT showed thickening of the gastric wall divided into two parts and slightly swollen lymph nodes on the side of the gastric lesser curvature. On a diagnosis of gastric collision tumor, total gastrectomy was performed. Pathological findings showed collision of these tumors deeper than the submucosal layer with interposition of the normal mucosa. The proximal lesion was diagnosed as gastric carcinoma with lymphoid stroma related to Epstein-Barr virus infection, while the distal lesion was diagnosed as moderately differentiated adenocarcinoma. Using Epstein-Barr virus-encoded RNA in situ hybridization, this case was confirmed as a ‘true' collision tumor.
