[1410] SOX11 Expression in B-Cell Lymphoma and Identification of the First Putative Cases of Cyclin D1-Negative Blastoid Mantle Cell Lymphoma.

Weifen Zeng, Kai Fu, Megan S Lim, Neeraj Kumar, Sarah Ondrejka, Eric Hsi. Cleveland Clinic; University of Nebraska Medical Center, Nebraska; University of Michigan, Ann Arbor

Background: SOX11, a neural transcription factor, has been reported as a specific marker for mantle cell lymphoma (MCL). We report our experience in the evaluation of SOX11 expression pattern in B cell non-Hodgkin lymphoma (B-NHL) types and identify the first reported cases of cyclin D1 negative blastoid MCL.
Design: 145 cases of B-Non Hodgkin lymphoma (B-NHL) were included in this study: 31 MCL (30 cyclin D1+ and 1 cyclin D1 negative MCL, reported previously), 75 DLBCL (including 8 CD5+ DLBCL), 5 Burkitt lymphoma (BL), 5 small lymphocytic lymphoma (SLL), 5 marginal zone lymphoma (MZL), 10 follicular lymphoma (FL), 5 lymphoplasmacytic lymphoma (LPL). 5 cases of lymphoblastic lymphoma (2 precursor B and 3 precursor T) were also included. Because of the potential use of SOX11 in identifying cyclin D1-negative MCL, we also examined 4 cases of suspected blastoid MCL cases that were cyclin D1 negative. Tissue microarray and whole tissue sections were stained for SOX11 (1:50, Sigma/Atlas antibodies) on an automated stainer (Discovery, Ventana Medical Systems). Positive SOX11 staining was defined as >10% of tumor cells with nuclear reactivity.
Results: Nuclear expression of SOX11 was found in cyclin D1+ MCL (30/30, 100 %) and the cyclin D1-negative MCL with typical morphology (1/1), BL (1/5, 20%), LBL (4/5, 80%), while all DLBL (including CD5+ DLBCL), SLL, MZL, FL, LPL cases were negative. In MCL, the mean % positive cells was 80% (range 20-100%). The four suspected cases of blastoid MCL (identified by enlarged nuclei with blastoid chromatin, mild nuclear irregularity, presence of epithelioid histiocytes, coexpression of CD5, lack of TdT, and Ki-67 index >75%) were also SOX11+.
Conclusions: We confirmed prior reports that SOX11 nuclear expression is a specific marker for MCL. SOX11 is expressed in cyclin D1 negative MCL with typical morphology. To our knowledge, this is the first report regarding its use in identifying cases of cyclin D1 negative blastoid MCL, especially when the differential diagnosis of CD5 positive DLBCL (negative for SOX11) was considered. Although SOX11 can also be detected in some BL and LBL, the distinct phenotypic and molecular features of these lymphomas would allow one to distinguish these cases from a potential cyclin D1-negative blastoid MCL.
Category: Hematopathology

Monday, February 28, 2011 8:30 AM

Platform Session: Section B, Monday Morning


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