Detection of Epstein-Barr virus DNA in gastric carcinoma with lymphoid stroma

Gastric carcinoma with lymphoid stroma (GCLS) was considered to be one of the virus-associated neoplasms. However, the precise mechanism of Epstein-Barr virus (EBV) oncogenesis for GCLS remains unclear. We used polymerase chain reaction (PCR) and DNA in situ hybridization (ISH) methods to detect the presence of EBV DNA in 14 cases of gastric carcinoma, including 8 cases of GCLS. Epstein-Barr virus DNA was detected by both PCR and ISH in 3 of the 8 GCLS cases (37.5%) and was negative in the other 6 cases of non-GCLS. In situ DNA hybridization showed that the EBV DNA was in the carcinoma cells in all cases that were positive by PCR. Among the positive cases, one early gastric carcinoma showed that EBV DNA was not only in the carcinoma cells, but also in the normal epithelium. This study provides the interpretation of the finding of EBV DNA in nonneoplastic gastric epithelium. Some genetic changes may be initiated in the EBV-infected nonneoplastic cells, which would lead to oncogenesis.