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. (C) 2013 Elsevier GmbH. All rights reserved.
