INCONSISTENT ASSOCIATION OF EPSTEIN-BARR-VIRUS WITH CD56 (NCAM)-POSITIVE ANGIOCENTRIC LYMPHOMA OCCURRING IN SITES OTHER THAN THE UPPER AND LOWER RESPIRATORY-TRACT

We previously described nine cases of angiocentric lymphoma of a possi ble natural killer (NK)-cell lineage with a surface CD3- CD56+ phenoty pe occurring in sites other than the upper and lower respiratory tract . This study was performed to investigate the association of Epstein-B arr virus (EBV) with these lymphomas, using the polymerase chain react ion (PCR) for the presence of EBV-DNA, in situ hybridization (ISH) for EBV-encoded small RNAs (EBERs) and immunohistology for EBV-determined nuclear antigen-2 (EBNA-2) and latent membrane protein-1 (LMP-1) in p araffin sections. PCR and ISH produced almost identical results, and E BERs were identified in the nuclei of the lymphoma cells of three case s, two of which exhibited LMP-1 in the cytoplasm of tumour cells witho ut EBNA-2 expression. Molecular genetic analysis revealed EBV to be in corporated into these three EBER-positive cases either clonally or bic lonally. It was revealed by re-evaluation of their morphology with the established EBV status on each case that, in contrast to the rather v ariable and irregular cellular composition of the EBV-positive tumours , the EBV-negative tumours stood out because of their remarkably unifo rm 'blastoid' appearance, and could be grouped as blastic NK-cell lymp homa. The relationship of the EBV-positive cases with nasal NK-cell tu mours has yet to be clarified.