Lymphoepithelioma-like carcinoma of the stomach: A subset of gastric carcinoma with distinct clinicopathological features and high prevalence of Epstein-Barr virus infection

BACKGROUND/AIMS: To evaluate the clinicopathological features of lymphoepithelioma-like carcinoma of stomach in Taiwan. METHODOLOGY: Of 379 patients with gastric adenocarcinoma, from 1993 to 1996, 6 of them with lymphoepithelioma-like carcinoma of stomach were retrospectively studied. RESULTS: Five patients were females and one patient was male. Their age ranged from 51-75 years with a mean age of 61.5 years. Endoscopically, 2 patients were initially diagnosed as early gastric cancer and the other 4 were diagnosed as advanced gastric cancer. Three patients had tumors located in the lower third of the stomach, while the other three tumors were located in the middle and upper third. Two tumors invaded into the serosal layer and the other four lesions were confined at submucosal and muscular layers. Using the in situ hybridization method, all 6 patients (100%) had positive nuclear Epstein-Barr virus-encoded small RNA signals in the tumor cells but not in the surrounding lymphoid stroma and non-neoplastic gastric mucosa. Helicobacter pylori was found in 4 (66.7%) of the cases; The mean follow-up period of the 6 patients was 27 months. Five patients were free of the disease. Lymph node involvement and mesenteric implantation was noted in one-patient in which cancer recurred 1 year after gastrectomy. CONCLUSIONS: Lymphoepithelioma-like carcinoma of stomach in this study revealed a female predominance, preferential localization in the proximal part of the stomach, better prognosis, and a high association with Epstein-Barr virus infection.