* Cytopenias defined as: hemoglobin <10 g/dL; platelet count <100 × 109/L; and absolute neutrophil count <1.8 × 109/L. Rarely, MDS may present with mild anemia or thrombocytopenia above these levels. PB monocytes
must be <1 × 109/L
† If SF3B1 mutation is present
‡ One percent PB blasts must be recorded on at least 2 separate occasions.
§ Cases with ≥15% ring sideroblasts by definition have significant erythroid dysplasia, and are classified as MDS-RS-SLD.
¥ Unbalanced: Loss of chromosome 7 or del(7q), del(5q), isochromosome 17q or t(17p), loss of chromosome 13 or del(13q), del(11q), del(12p) or t(12p), del(9q), idic(X)(q13). Balanced: t(11;16)(q23.3;p13.3), t(3;21)(q26.2;q22.1), t(1;3)(p36.3;q21.2), t(2;11)(p21;q23.3), inv(3)(q21.3q26.2)/t(3;3)(q21.3;q26.2), t(6;9)(p23;q34.1).
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MDS with single lineage dysplasia (MDS-SLD)
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1
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1-2
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< 15% / < 5% †
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BM < 5%, PB < 1%, no Auer rods
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Any, unless fulfils all criteria for MDS with isolated del(5q)
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MDS with multilineage dysplasia (MDS-MLD)
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2 - 3
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1 - 3
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< 15% / < 5% †
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BM < 5%, PB < 1%, no Auer rods
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Any, unless fulfils all criteria for MDS with isolated del(5q)
|
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MDS with ring sideroblasts (MDS-RS)
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|
|
|
|
|
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MDS-RS with single lineage dysplasia (MDS-RS-SLD)
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1
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1 - 2
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≥ 15% / ≥ 5% †
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BM < 5%, PB < 1%, no Auer rods
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Any, unless fulfils all criteria for MDS with isolated del(5q)
|
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MDS-RS with multilineage dysplasia (MDS-RS-MLD)
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2 - 3
|
1 - 3
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≥ 15% / ≥ 5% †
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BM < 5%, PB < 1%, no Auer rods
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Any, unless fulfils all criteria for MDS with isolated del(5q)
|
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MDS with isolated del(5q)
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1 - 3
|
1 - 2
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None or any
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BM < 5%, PB < 1%, no Auer rods
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del(5q) alone or with 1 additional abnormality, except loss of chromosome 7 or del(7q)
|
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MDS with excess blast
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|
|
|
|
|
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MDS-EB-1
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0 - 3
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1 - 3
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None or any
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BM 5% - 9% or PB 2% - 4%, no Auer rods
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Any
|
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MDS-EB-2
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0 - 3
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1 - 3
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None or any
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BM 10% - 19% or PB 5% - 19% or Auer rods
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Any
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MDS, unclassifiable (MDS-U)
|
|
|
|
|
|
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MDS-U with 1% blood blasts
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1 - 3
|
1 - 3
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None or any
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BM <5%, PB =1% ‡, no Auer rods
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Any
|
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MDS-U with single lineage dysplasia and pancytopenia
|
1
|
3
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None or any
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BM <5%, PB <1%, no Auer rods
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Any
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MDS-U based on defining cytogenetic abnormality
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0
|
1 - 3
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<15% §
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BM <5%, PB <1%, no Auer rods
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MDS-defining abnormality ¥
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