[1208] Application of 2008 WHO Classification Criteria for Myelodysplastic Syndromes (MDS) without Excess Blasts: Observations from Cancer and Leukemia Group B Study 10105
RP Hasserjian, P Gupta, K Donohue, K Owzar, RA Larson, F Racke, CD Bloomfield. MGH, Boston, MA; University of Minnesota, Minneapolis, MN; Duke University, Durham, NC; University of Chicago, Chicago, IL; Ohio State University, Columbus, OH
Background: The new 2008 WHO Classification of MDS emphasizes the number of lineages affected by dysplasia, but its impact on the classification of MDS entities has not yet been assessed, nor has the correlation between dysplasia and cytopenia in each lineage been well-characterized.
Design: A single observer reviewed bone marrow biopsies, aspirates, and peripheral smears from 59 cases diagnosed as MDS without excess blasts (<5%) and scored percentage of dysplastic forms in each lineage and ring sideroblasts. In combination with peripheral counts and cytogenetics results, cases were classified according to both the 2001 and updated 2008 WHO criteria. We also assessed the relationship of dysplasia and ring sideroblasts to cytopenias and International Prognostic Scoring System (IPSS) score.
Results: The diagnoses by classification system are shown in Table 1.
Classification of 59 cases| Diagnosis | WHO 2001 | WHO 2008 |
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| RA | 0 | 0 | | RCUD | NA | 2 | | RARS | 10 | 8 | | RCMD | 21 | 41 | | RCMD-RS | 6 | NA | | MDS with isolated del(5q) | 2 | 2 | | MDS,U | 19 | 2 | | Not MDS | 1 | 4 | RA=refractory anemia; RC=refractory cytopenia; UD=unilineage dysplasia; RS=ring sideroblasts; MD=multilineage dysplasia; U=unclassifiable; NA=not applicable
By 2008 criteria, 4 cases were not MDS, including 2 cases of RARS with marked thrombocytosis, 1 case of myelodysplastic/myeloproliferative neoplasm, unclassifiable, and 1 case that had insufficient dysplasia. There was no significant correlation between the presence of dysplasia and cytopenia in the erythroid, granulocytic, or megakaryocytic lineages. The presence of any ring sideroblasts correlated with anemia (p=0.003), lack of thrombocytopenia (p=0.01), and lack of granulocytic dysplasia (p=0.01), and was borderline correlated with lack of neutropenia (p=0.05). Granulocytic dysplasia was borderline correlated with poor prognosis IPSS karyotype score (p=0.10).
Conclusions: Lineage-specific dysplasia in MDS does not correlate with cytopenia in any lineage, although granulocytic dysplasia is borderline associated with a poor prognosis karyotype. The allowance of RCMD with a single cytopenia and non-erythroid RCUD in the 2008 Classification has markedly reduced the number of cases that would previously be classified as MDS,U.
Category: Hematopathology
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 199, Wednesday Afternoon
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