Epstein-Barr virus and gastrointestinal lymphomas in Korea

To analyze the association of Epstein-Barr virus (EBV) with gastrointestinal non-Hodgkin's lymphomas; arising in immunocompetent patients, 56 consecutive cases of gastrointestinal lymphomas (B-cell: 52 cases, T-cell: 3 cases, T/NK-cell: I case) occurring in the stomach (33 cases), intestine (22 cases) and esophagus (I case) were investigated for the presence of EBV using polymerase chain reaction analysis as a screening method followed by EBER-1 RNA and DNA in situ hybridization (ISH) and immunohistochemistry for the expression of latent membrane protein I (LMP-I). Forty-seven cases demonstrated extractable DNA and EBV DNA was detected only in 4 cases. Among them, RNA (EBER-1) and DNA ISH analysis confirmed the presence of the EBV genome in tumor cells in 3 cases (T/NK-cell lymphoma of ileum, gastric high-grade B-cell lymphoma of mucosa-associated lymphoid tissue, gastric diffuse large B-cell lymphoma). Only the T/NK cell lymphoma showed diffuse positivity of turner cells while 2 gastric B-cell lymphomas; demonstrated a scattered positive reaction and no cases expressed LMP-I. Nine cases without extractable DNA by the PCR method showed no nuclear signal by EBER-1 ISH. These findings suggest that most sporadic primary gastrointestinal lymphomas in Korea are not associated with EBV.