[1607] Detection of Clonal T-Cell Large Granular Lymphocytes in Low-Grade Myelodysplastic Syndrome

Xiaohui Zhang, Lynn C Moscinski, Reza Setoodeh, Deniz Peker, Ling Zhang. University of South Florida College of Medicine, Tampa, FL; H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL

Background: Proliferation of clonal T-cell large granular lymphocytes (T-LGL) can coincidentally occur with MDS. However, it is not clear whether or not concurrent T-LGL proliferation in MDS has distinctive features from classic T-LGL leukemia. This study aims to analyze the clinicopathological features of concomitant T-LGL in low-grade MDS, in comparison with true T-LGL leukemia.
Design: Data from patients with low-grade MDS or T-LGL leukemia between 1/2005 and 2/2010 were collected. The patients were divided into three groups: MDS with T-LGL (MDS-LGL), MDS only and T-LGL leukemia only. Laboratory and bone marrow parameters including peripheral complete blood counts (CBC), TCR gene rearrangement, and CD3+/CD57+ LGL cell counts were analyzed.
Results: LGL flow cytometry panel was performed on a total of 59 patients with low-grade MDS and flow cytometry data from 18 patients with T-LGL leukemia were collected for comparison. All T-LGL cases were with no morphologic dysplasia. Clonal T-LGL cells were identified in 25 of 59 patients with MDS (42%) and 100% in patients with T-LGL leukemia. Clonal TCR-β or/and TCR-γ gene rearrangements were detected in 24/25 (96%) in MDS-LGL, 10/34 (29.4%) in MDS only and 17/17 (100%) in T-LGL leukemia (P=0.001). The immunophenotype of the T-LGL cells was typically CD3+/CD57+/CD7 dim+/CD5 dim+/CD8+. The CD3+/CD57+ LGL cells were increased in 6 of 25 MDS-LGL (>=300 cells/μL), comparing with that in 2 of 33 MDS only patients and that in 12 of 17 LGL leukemia patients (p=0.01). The clonal T-LGL cell counts in MDS were often lower than 500 cells/μL (56 of 58 patients), while 9 of 17 T-LGL leukemia patients have higher than 500 T-LGL cells. Absolute neutrophil count (ANC), hemoglobin (g/dL) and platelet count have no significant differences among the three groups (p>0.5). Age-adjusted hypocellularity is infrequently noted in all three groups, while erythroid hypoplasia (M:E>5:1) was observed in 9 of 25 MDS-LGL, 5 of 33 in MDS only, and 2 of 12 LGL leukemia patients (p=0.066).
Conclusions: Clonal T-LGL proliferation is frequently detected in low-grade MDS. Except for CD3+/CD57+ LGL cell count, peripheral blood cell counts, immunophenotypes, and TCR gene rearrangements have no significant differences between these two categories. Additional bone marrow biopsy, along with clinical presentation, imaging study and cytogenetics, are necessary to separate MDS-LGL from true LGL leukemia.
Category: Hematopathology

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 233, Monday Morning

 

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