[1397] CD4-Positive Diffuse Large B-Cell Lymphoma: An Aggressive Clinical Variant

Mohammad O Hussaini, TuDung T Nguyen, Friederike H Kreisel, Anjum Hassan, John Frater. Washington University, St. Louis, MO

Background: The expression of T-cell associated antigens is not frequently identified in benign lymphocytic proliferations but is noted in up to 25% of B-cell non-Hodgkin lymphomas. However, CD4 expression is exceedingly rare in diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) with only 4 cases reported in the world literature. We report five cases of CD4+ DLBCL, NOS and one case of CD4+ primary mediastinal large B-cell lymphoma (PMLBCL).
Design: Cases were identified by searching the Copath database at Barnes Jewish Hospital/Washington University (WU/BJC) using the terms “large B-cell lymphoma” and “CD4” in any field. Each hit was then reviewed to identify cases of diffuse large B-cell lymphoma with CD4 expression. Clinical data were acquired from WU/BJC Clinical Desktop, CoPath, and Touchwork databases, as well as by clinician interview.
Results: Five cases of CD4+ DLBCL and one case of CD4+ PMLBCL were identified. No sex predilection was seen (3 males, 3 females). Average age was 56 years (range: 22-79). The neoplastic cells expressed CD45 (4/4 tested cases) and CD20 (5/6 tested cases). In the CD20 negative case, a clonal IgH gene rearrangement was detected. BCL2 and BCL6 expression were seen in 3/3 tested cases, suggesting a germinal center origin. In addition to CD4, aberrant expression of T-cell antigens CD2 and CD5 was noted in two cases each and CD7 in one case. CD3 was essentially negative. IgH was clonally rearranged in one tested case. A TCR gene rearrangement was not found in one tested case. Lymph nodes were the most common site of involvement (67%). All patients received multi-agent chemotherapy +/- radiation. One patient underwent stem cell transplant. Initial response to chemotherapy was frequently observed (4/4 cases). Average overall survival (n=6) was 44.2 months. For those who died (n=3), average survival was only 11.7 months.
Conclusions: CD4 expression in DLBCL raises interesting questions of lineage commitment and plasticity. CD4 positivity in DLBCL is rare, but care should be exercised not to diagnose these as T-cell lymphomas. A subset of these lymphomas may behave aggressively.
Category: Hematopathology

Monday, March 4, 2013 1:00 PM

Poster Session II # 192, Monday Afternoon

 

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