CLINICAL FEATURES OF EPSTEIN-BARR VIRUS-ASSOCIATED GASTRIC CARCINOMA

Abstract

Epstein-Barr virus (EBV) is an oncogenic human herpesvirus involved in the development of approximately 10％ of gastric cancers (GCs). EBV-associated GC (EBVaGC) predominantly localizes in the gastric body-cardia. EBVaGC is histologically a diffuse-type carcinoma accompanied by infiltration of abundant lymphocytes. Endoscopically, EBVaGC appears as superficially depressed lesions in the early stages and as ulcerated lesions in the advanced stages. EBVaGCs are accompanied by the formation of submucosal nodules of carcinoma with lymphoid stroma, resulting in characteristic submucosal tumor-like findings. Endoscopic ultrasound reveals a hypoechoic mass in the third hyperechoic layer reflecting submucosal nodules in the lymphoid stroma. EBVaGC occurs in gastric mucosa affected by chronic atrophic gastritis caused by Helicobacter pylori infection. Only a small percentage of patients with EBVaGC have lymph node metastases even if it invades the submucosa; thus, endoscopic resection may be more frequently performed. Since the presence of EBV affects treatment strategies for gastric cancer, the importance of diagnosing EBVaGC is increasing.