[1295] EBV Positive Diffuse Large B-Cell Lymphoma in the Elderly: A Diagnostic Entity?

GC Caponetti, A Torabi, K Fu, TC Greiner. University of Nebraska Medical Center, Omaha, NE

Background: According to the 2008 WHO classification, EBV+ diffuse large B-cell lymphoma of the elderly (EBV+DLBCLe) is a clonal B-cell lymphoma that occurs in patients who are over 50 years old and have no known past medical history (PMH) of immunodeficiency or lymphoma. Several reports suggest EBV+DLBCLe has a poor prognosis, accounts for 8-10% of DLBCL in Asian countries, and is rare in the US. However, clonality was not required for the diagnosis in any of these studies. We have observed that some cases of EBV+DLBCLe have comorbidities in their PMH, that could potentially explain an alteration of the immune system besides elderly age. The objectives of this study were twofold; 1) determine the incidence of EBV+DLBCLe in the US, and 2) identify what comorbidities were also present.
Design: EBERs in situ hybridization was performed on a TMA of 84 DLBCL cases (over 50 years of age) that were previously selected on the basis of the availability of frozen tissue. In addition, a search for EBV+ (by EBERs or LMP1) lymphoproliferative disorders (LPDs) was conducted in our database of all tissue biopsies from 1995 to 2009. The histology of the EBV+ cases was reviewed, and the PMH was examined to identify comorbidities. A case was declared clonal if one of the following was present: kappa/lambda light chain restriction, IgH rearrangement, or abnormal karyotype.
Results: In the selected group of 84 cases of DLBCL in the TMA, 3 (3.5%) were found to be EBER+, but 2 of these did not meet the WHO criteria for EBV+DLBCLe, due to an exclusionary diagnosis of lymphomatoid granulomatosis in one and the lack of clonality in the other. Therefore, only 1 (1.2%) of the 84 cases met the WHO criteria of EBV+DLBCLe. The search of the large database identified a total of 129 cases of EBV+ LPDs. Seven cases, with an average age of 63 years, met the criteria for EBV+DLBCLe. Of these 7 clonal cases, two had a PMH significant for carcinoma, and one had a PMH of low-dose corticosteroids for COPD. Six cases of EBV+ polymorphic LPD, with an average age of 79, but without evidence of clonality to-date, had a PMH of diabetes (n=1), carcinoma (n=1) and Crohn's disease (n=1).
Conclusions: EBV+DLBCLe is rare in the US compared to Asian countries. This series suggests that detailed review of the medical record may identify comorbidities in some cases, that could act as predisposing factors in the development of these DLBCLs. It is unlikely that EBV+DLBCLe is a diagnostic entity, but rather EBV+ may be just a biologic indicator or a prognostic marker.
Category: Hematopathology

Monday, March 22, 2010 2:00 PM

Platform Session: Section B, Monday Afternoon

 

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