The role of Epstein-Barr virus in lymphoepithelioma-like carcinomas.

Epstein-Barr virus (EBV) has been implicated in the pathogenesis of a variety of lymphoproliferative disorders and several epithelial neoplasms, including undifferentiated nasopharyngeal carcinoma (UNPC; lymphoepithelioma). Lymphoepithelioma-like carcinomas (LEC) are tumors with morphologic features identical to UNPC that occur outside the nasopharynx. To determine whether EBV is associated with LEC, the authors conducted a comprehensive literature review of all pathologically documented LEC reported to date in the English literature. In summary, EBV is associated consistently with LEC from only four anatomic sites: stomach, salivary gland, lung, and thymus. Racial and/or geographic factors influence the association of EBV with LEC in some of these organs. Specifically, the association of EBV with LEC of the salivary gland and lung is restricted to Asian patients, whereas the association of EBV with gastric and thymic LEC is independent of race. The presence or absence of EBV in LEC does not appear to be prognotically important in those cases studies to date.