[1385] CD10-Positive, Low Grade B-Cell Lymphomas with Marginal Zone-Like Features

Jennifer L Guthrie, Jacek Polski. University of South Alabama, Mobile, AL

Background: Marginal zone lymphoma (MZL) and follicular lymphoma (FL) are common lymphomas often seen in extra-nodal locations and may create diagnostic difficulties in small biopsy samples. In general, FL is CD10-positive while MZL is CD10-negative. Although there are case reports of CD10-positive MZL, the reported incidence is rare. Cytogenetic or molecular testing, including FISH and PCR, can help differentiate between these lymphomas.
Design: Pathology files were searched for CD10-positive cases of low-grade B-cell lymphomas with marginal zone-like morphological features and with available cytogenetic/molecular testing results. Marginal zone-like morphology was defined by a predominately diffuse or marginal zone pattern, monocytoid cytology, plasma cell differentiation, or lymphoepithelial lesions. Cases with typical FL morphology were excluded.
Results: Eight cases of lymphomas were identified for this review. Of these eight cases, seven were extra-nodal and one was nodal. There were three females and five males ranging from 37 to 88 years old. All of the cases were positive for CD10 by either immunohistochemistry or flow cytometry. All cases were tested for Bcl-2 rearrangement by FISH or PCR. Five cases had Bcl-2 rearrangement confirming the diagnosis of FL. Three were negative for Bcl-2 rearrangement supporting the diagnosis of MZL. Of the three Bcl-2 negative cases, two had MALT1 rearrangements, and one had trisomy 3.
Conclusions: The study documents a well-known fact that some FL can have marginal zone-like morphological features. However, some of the CD10-positive, low-grade B-cell lymphomas with marginal zone-like morphology represent true MZL. Our results demonstrate the necessity of cytogenetics/molecular testing for final classification of CD10-positive, low-grade B-cell lymphomas with marginal zone-like features, especially in extra-nodal sites.
Category: Hematopathology

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 256, Tuesday Afternoon


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