The Expression of EBV in Diffuse Large B-Cell Lymphomas (DLBCL) and Its Correlation with Lymphoma Subtypes as Defined in the WHO 2008 Classification
A Uner, N Akyurek, S Abdullazade, N Uzum, A Saglam. Hacettepe University, Medical Faculty, Ankara, Turkey; Gazi University, Medical Faculty, Ankara, Turkey
Background: Diffuse Large B-Cell Lymphoma (DLBCL) is the most common lymphoma type in our country. New subtypes and variants have been recognized within DLBCL group in the 2008 WHO Classification of Tumours of Hematopoetic and Lymphoid Tissues. The accumulated evidence has shown the importance of EBV in the pathogenesis of various lymphomas. In particular, new disease entities such as EBV positive DLBCL of the elderly have been defined based on the expression of EBV.
Design: DLBCL cases diagnosed between 1999 and 2009 were retrieved from the archives of our departments. All the sections for these cases were re-evaluated and 370 cases in which parafin blocks were available were used to construct tissue microarrays. Each case was represented by 2-4, 1mm thick cores in the receiving blocks. Four micrometer sections were obtained form these blocks and the presence of EBV small ribonucleic acids was examined by in situ hybridization using EBER oligonucleotids.
Results: The DLBCL cases included 183 male and 187 female patients with an age range of 8-101 years. A total of 14 cases (4%) showed EBV expression. These cases included two cases of primary DLBCL of the CNS (in immunocompetent individuals), 1 case of secondary brain involvement of a systemic DLBCL, 1 case of transformed MALT lymphoma, two cases with Burkitt-like morphology. The remaining 8 cases were classified as EBV positive DLBCL of the elderly based on their age (between 55 and 83), the lack of any known immunodeficiency or prior lymphoma in the clinical history. Three of the cases showed extranodal (tonsil) and five showed nodal presentation. One of these cases was originally classified as T-cell Rich B-cell Lymphoma; all the remaining cases had classical DLBCL morphology. These cases were evalauted for the presence of translocations involving bcl-2, bcl-6 and c-myc using breakapart FISH probes. An abnormality was identified in only one case which showed the presence of breaks in all three genes. Follow-up information could be obtained in seven of the cases. Four of the cases had died within one year following diagnosis, one case was in complete remission (follow-up 8 months) and two cases were in partial remission (6 and 17 months) after the diagnosis.
Conclusions: In our study group EBV expression is not prevalant in DLBCL and EBV positive DLBCL is a rare entity with poor prognosis.
Monday, March 22, 2010 1:00 PM
Poster Session II # 136, Monday Afternoon