[1441] CD5-Positive Nodal Marginal Zone Lymphoma: A Clinicopathologic Study of 7 Cases

Jesse Jaso, C Cameron Yin, Christine E Jabcuga, L Jeffrey Medeiros, Lei Chen. The University of Texas Health Science Center at Houston, Houston, TX; The University of Texas MD Anderson Cancer Center, Houston, TX

Background: Nodal marginal zone lymphoma (NMZL) is characterized by nodal disease without extranodal or splenic involvement, a non-specific immunophenotype with lack of CD5 expression, and an increased tendency for disseminated disease. Bone marrow involvement occurs in approximately 50% of cases. Scattered cases of CD5-positive NMZL have been reported, yet the clinicopathologic features remain incompletely described. We studied 7 cases of CD5-positive NMZL to assess if these cases represent a distinct subtype of NMZL.
Design: We searched the database at our hospital for cases of NMZL that were positive for CD5 by immunohistochemistry (IHC) and/or flow cytometric immunophenotyping (FCI). Cases with extranodal or splenic involvement were excluded. Clinicopathologic data were obtained from medical records. Cytogenetic analysis was performed on 5 cases.
Results: We identified 7 cases of CD5-positive NMZL representing <1% of all NMZL at our hospital (2 men, 5 women, median age 55 years). At presentation, all had disseminated disease with generalized lymphadenopathy. Bone marrow was involved in 6 patients assessed. None had cytopenias, elevated serum lactate dehydrogenase, B-symptoms, or hepatitis C infection. One had lymphocytosis, and one had a monoclonal IgG protein. ß2 Microglobulin was elevated in 4. All neoplasms showed features of NMZL, including architectural effacement with small to medium-sized cells and occasional large cells in a paracortical or marginal zone distribution with follicular colonization and plasma cell differentiation. CD5 was positive by IHC (7/7) and FCI (4/4). The lymphoma cells also expressed CD20 (7/7), CD19 (4/4), BCL-2 (5/5), CD22 (2/2), Pax-5 (2/2), and CD43 (1/3). All were negative for CD10, CD23, and cyclin D1. A diploid karyotype was present in all 5 cases assessed. With a median follow-up of 32 months (range: 10-154), among 6 patients who received R-CHOP, 3 were alive with disease including 1 patient who also received stem cell transplant due to transformation to diffuse large B-Cell lymphoma, 2 had complete remission, and 1 died of disease. One patient was observed with no treatment, and was alive with disease. Overall survival at 5-years was 85.7%.
Conclusions: CD5 expression is a rare occurrence in NMZL. CD5+ cases share many clinicopathologic features with CD5- disease, but appear to have a higher rate of bone marrow involvement. Overall survival remains excellent with appropriate therapy.
Category: Hematopathology

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 212, Monday Morning


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