Inconsistent association of Epstein-Barr virus with CD56 (NCAM)-positive angiocentric lymphoma occuring in sites other than the upper and lower respiratory tract

We previously described nine cases of angiocentric lymphoma of a possible natural killer (NK)‐cell lineage with a surface CD3− CD56+ phenotype occurring in sites other than the upper and lower respiratory tract. This study was performed to investigate the association of Epstein‐Barr virus (EBV) with these lymphomas, using the polymerase chain reaction (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 paraffin sections. PCR and ISH produced almost identical results, and EBERs were identified in the nuclei of the lymphoma cells of three cases, two of which exhibited LMP‐1 in the cytoplasm of tumour cells without EBNA‐2 expression. Molecular genetic analysis revealed EBV to be incorporated into these three EBER‐positive cases either clonally or biclonally. It was revealed by re‐evaluation of their morphology with the established EBV status on each case that, in contrast to the rather variable and irregular cellular composition of the EBV‐ positive tumours, the EBV‐negative tumours stood out because of their remarkably uniform ‘blastoid’ appearance, and could be grouped as blastic NK‐cell lymphoma. The relationship of the EBV‐positive cases with nasal NK‐cell tumours has yet to be clarified.