Evaluation of the role of Epstein-Barr virus in cases of nodal or extranodal T- and NK-cell lymphoma using eber in situ hybridization.

Various racial and geographic differences have been observed in studies questioning the role of Epstein-Barr virus (EBV) infection in the etiology of T- and NK-cell lymphomas. The aim of this study was to evaluate the relationship of EBV with nodal or extranodal (skin excluded) T- and NK-cell lymphoma subtypes encountered in our geographic area. Sixty-two cases of peripheral T-cell lymphoma were included in the study. EBV-encoded early RNA (EBER) was detected by in situ hybridization. The distributions of T- and NK-cell lymphoma subtypes were as follows: 32 peripheral T-cell lymphomas, unspecified (PTCL, NOS), 13 anaplastic large-cell lymphomas (ALCL), 8 angioimmunoblastic T-cell lymphomas (AITCL), 4 extranodal NK/T-cell lymphomas, nasal type (NKTCL), 3 enteropathy-type T-cell lymphomas (ETTCL), 1 hepatosplenic T-cell lymphoma (HSTCL), and 1 subcutaneous panniculitis-like T-cell lymphoma (SPTCL). Using a cut-off value of >25% of EBER-positive neoplastic lymphoid cells, EBV was positive in 22.6% of all cases. According to subtype, the neoplastic cells of 31.3% of PTCL, NOS and 100% of extranodal NKTCL, nasal type were EBER positive, whereas some cases of ALCL, AITCL, and ETTCL presented EBER-positive non‑neoplastic cells, and all cells of HSTCL and SPTCL were EBV negative. Extranodal NKTCL, nasal type, presented the strongest association with EBV, followed by PTCL, NOS.