Gastric carcinoma with lymphoid stroma: incidence of EBV and Helicobacter pylori infection.

Lymphoepithelioma-like carcinoma (LELC) of the stomach is reported to be associated with Epstein-Barr virus (EBV) and to have a better prognosis than typical adenocarcinoma. However, the incidence of EBV and its association with Helicobacter pylori is controversial. In our series, 9 of 370 (2.4%) cases of gastric adenocarcinoma were LELC. Formalin-fixed, paraffin-embedded LELC tissue was immunostained with monoclonal antibodies against CD3, CD20, and Ki-67. Warthin-Starry stain for H. pylori and in situ hybridization for EBV were performed. As a control, 21 cases of adenocarcinoma with prominent lymphoid stroma were compared with LELC. The most common location of LELC was the body of the stomach (five cases), followed by the cardia (two cases), whereas the antrum was the most common site for the control group. There were no significant differences in age, sex, or lymph node metastasis between the LELC and control groups. The mean Ki-67 index was similar (38.2% in LELC versus 35.3% in control). H. pylori was found in 2 LELC cases (22%) and 6 controls (28.5%). EBV was positive in 7 LELC cases (77.8%) and 4 controls (19.0%). All patients with LELC are alive and well, whereas three patients have died of their disease in the control group. Although EBV appeared to be a contributing factor, H. pylori had a minor role in LELC. There were no clinicopathologic differences between LELC and the control group, except for the location of the tumor in the body of the stomach and the tendency toward a better prognosis in LELC.