Epstein-Barr virus (EBV) positive diffuse large B cell lymphoma of the elderly-experience of a single center from Turkey.

In the 2008 WHO lymphoma classification, 'EBV-positive diffuse large B cell lymphoma (DLBCL) of the elderly is included as a new provisional entity. We aimed to evaluate the morphological, immunophenotypic, and clinical characteristics of the cases diagnosed as 'EBV-positive DLBCL of the elderly' in our center and compared them with the 'EBV-negative DLBCL' patients older than 50 years of age. EBV status was detected by Epstein-Barr early RNA (EBER) in situ hybridization analysis. By immunohistochemistry, a panel of antibodies for CD10, Bcl-2, Bcl-6, IRF4/MUM1, CD30, and Ki67 was performed. Out of 149 DLBCL patients older than 50 years, without any known history of immunodeficiency or prior lymphoma, eight patients who fulfill the criteria were re-evaluated. Five patients were male and three were female, with a median age of 67.6 years. Four patients presented with nodal involvement; others presented with bone and soft tissue, bone marrow, and spleen infiltrations. Five cases revealed predominantly monomorphic morphology, one also contained focal areas consistent with polymorphous subtype; and three patients revealed a polymorphous infiltrate. When classified according to 'Hans criteria', five were non-GCB, and three were of the GCB cell phenotype. All cases with polymorphous morphology were revealed to be of the non-GCB cell phenotype, and all expressed IRF4/MUM1. Two patients died with disease, four patients are alive and in complete remission following R-CHOP therapy, and two patients have just recently been diagnosed. When compared with the EBV-negative group, there are no reliable morphological and immunohistochemical features indicating EBV positivity. Therefore, EBER in situ hybridization analysis is necessary to identify 'EBV-positive DLBCL of the elderly'. Further studies are needed to fully understand the details of this disease, which can lead to new treatment modalities.