[1386] Myelodysplastic Syndrome with DEL(5q): A Comprehensive Analysis of 24 Cases from One Institution.

Shalini Verma, Julia T Geyer, Shivakumar Subramaniyam, Susan Mathew, Rosanny Espinal-Witter, Daniel M Knowles, Attilio Orazi. Weill Cornell Medical College, New York

Background: Del(5q) is the most frequent karyotypic abnormality in myelodysplastic syndrome (MDS), and the only subtype with a specific and effective targeted therapy (lenalidomide). The goal of this study was to provide a detailed hematopathologic analysis of a cohort of such patients treated at the same institution.
Design: MDS cases at initial diagnosis were divided in 3 groups: isolated del(5q) (n=7, group 1), del(5q) plus one additional chromosomal abnormality (n=3, group 2) and del(5q) as part of a complex karyotype (n=14, group 3). A detailed bone marrow (BM) analysis was performed, evaluating cellularity, M:E ratio, fibrosis, dysplasia, aspirate and core blast count (with CD34 immunostain), megakaryocyte morphology and number, aberrant megakaryocyte CD34 expression and megakaryoblasts. Clinical information including laboratory data was obtained. Chi-square test was used for statistical analysis.
Results: Patients in group 1 ranged from 62-84 (mean 74) years, with F:M=6, those in group 2 ranged from 60-87 (mean 73) years, F:M=2 and those in group 3 ranged from 43-83 (mean 66) years, with F:M=1.3. All patients had anemia. Patients in group 1 had a high MCV and normal platelets, while the majority of the remaining patients had normal MCV and thrombocytopenia. Patients in group 1 tended to have normal BM cellularity, no evidence of myeloid dysplasia, no increase in blasts or fibrosis and abundant hypolobated megakaryocytes. On the contrary, patients with additional cytogenetic abnormalities were significantly more likely to have increased cellularity, trilineage dysplasia, a higher number of blasts and BM fibrosis. 50% of patients in group 3 had aberrant CD34+ megakaryocytes and scattered CD42b+ megakaryoblasts. According to the WHO classification, group 2 contained 2 cases of RCMD and 1 RAEB. Group 3 had 1 RCMD, 8 RAEB and 5 t-MDS. Six patients were treated with lenalidomide. In group 1, 5/7 (71%) patients were alive with disease (AWD, mean 31 months after diagnosis) and 2 patients (29%) have died of disease (DOD, both after 5 years). Groups 2 and 3 had similar outcome; 6/17 patients (35%) were AWD (mean, 31 months) and 11/17 patients (65%) were DOD (mean, 10 months).
Conclusions: It has been suggested that MDS with del(5q) may represent a homogeneous group of lenalidomide-responsive patients. Our data shows that cases with an isolated del5(q) have morphologic and clinical features different from those with additional cytogenetic abnormalities. Thus, the mere presence of del(5q) does not appear to improve the expected prognosis in the latter group.
Category: Hematopathology

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 162, Monday Morning


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