CLONAL EPSTEIN-BARR-VIRUS IN LYMPHOEPITHELIOMA-LIKE CARCINOMA OF THE LUNG

Lymphoepithelioma of the nasopharynx is an undifferentiated carcinoma with a prominent lymphoid infiltrate. A consistent association with Ep stein-Barr virus (EBV) has been demonstrated over the years by a varie ty of methods. More recently, undifferentiated carcinomas with a simil ar morphology have been described in other anatomical locations, often of foregut origin. However, for lymphoepithelioma-like carcinoma, the association with EBV has been more tenuous, especially in Western cou ntries. Interestingly, these tumors have shown a geographic distributi on similar to nasopharyngeal lymphoepithelioma, with relatively high f requency of EBV positive cases in Asian patients. We report five cases of lymphoepithelioma-like carcinoma arising in the lung. In situ hybr idization revealed the presence of EBV in all cases with localization to the epithelial cells only. Southern-blot analysis from two cases re vealed the presence of clonal episomal EBV in the tumor tissue. These findings further support the hypothesis that EBV is also associated wi th lymphoepithelioma-like lung carcinomas and suggest that EBV infecti on has preceded the clonal expansion of the tumor.