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Abstract: Aggressive B-cell lymphomas incorporate a wide spectrum of lymphomas that pose challenges in diagnosis as well as treatment. We evaluated the clinicopathological features of 44 patients with aggressive B-cell lymphomas which were classified into 3 groups based on the World Health Organization 2008 classification as follows: including 30 cases of diffuse large B-cell lymphoma (DLBCL), 8 cases of Burkitt lymphoma (BL) and 6 cases of B-cell lymphoma, unclassifiable, with features intermediate between Burkitt lymphoma and diffuse large B-cell lymphoma (BCLU). Male predominance was observed in BL and BCLU groups and the mean age varied from 29 years in BL, 61 years in DLBCL and 70 years in BCLU. Patients with BCLU presented at more advanced stages and had a higher international prognostic index. By immunohistochemistry, they shared characteristics of both BL (including more frequent expression of SOX11) and DLBCL. FISH analyses showed three cases with more than one rearrangement: one MYC/BCL2 and two BCL2/BCL6, in addition to which one case with BCL2/IGH translocation and another with MYC rearrangement were also detected. The mean follow-up survival time of BCLU was 6.6 months, which was significantly shorter in comparison to DLBCL (31 months) and BL (30 months), respectively. The importance of recognizing this BCLU group relies on its different clinical course, poor prognosis and shorter survival than DLBCL and BL. An accurate diagnosis is critical for risk stratification and to improve therapeutic approaches and outcomes. [Copyright &y& Elsevier]

Diffuse large B-cell lymphoma (DLBCL), the most common group of malignant lymphomas, account for 30% of adult non-Hodgkin lymphomas. The 2008 World Health Organization (WHO) classification included a new entity, Epstein-Barr virus (EBV)+ DLBCL of the elderly, affecting patients aged 50 years or older. However, some reports of younger EBV+ DLBCL cases, without evidence of underlying immunosuppression, can be found. The role of EBV in tumor microenvironment composition in DLBCL is still not well understood. Our aim was to assess EBV presence and latency pattern as well as tumor T-cell population in an adult DLBCL series of Argentina. The study was conducted on biopsies from 75 DLBCL patients. EBERs expression was performed by in situ hybridization, while EBV gene expression was analyzed using real-time polymerase chain reaction. LMP1, LMP2A, EBNA2, EBNA3A, CD4, CD8 and Foxp3 expression was assessed by immunohistochemistry. Nine percent of cases showed EBV expression, with similar frequency among patients younger than 50 years and 50 years or older (13% and 8%, respectively). T-cell subsets were not altered by EBV presence. Latency type II was the most frequently observed, together with lytic gene expression in EBV+ DLBCL, with ≥20% of EBERs+ cells. These findings suggest that EBV+ DLBCL in our series was similar to the previously described in Asia and Latin-America, displaying latency II or III expression profile and no age-specific characteristics. Finally, EBV+ DLBCL may be an entity that is not only restricted to patients who are older than 50 years of age, in consequence the age cutoff revision may be a current goal., (© 2014 UICC.)