| Classification | Blasts | Cytogenetics | Variants | |
|---|---|---|---|---|
| MDS with defining genetic abnormalities: | ||||
| MDS with low blasts and isolated 5q deletion (MDS-5q) | <5% BM and <2% PB | 5q deletion alone, or with 1 other abnormality other than monosomy 7 or 7q deletion | ||
| MDS with low blasts and SF3B1 variantb (MDS-SF3B1) | Absence of 5q deletion, monosomy 7, or complex karyotype | SF3B1 | ||
| MDS with biallelic TP53 inactivation (MDS-biTP53) | <20% BM and PB | Usually complex | Two or more TP53 variants, or 1 TP53 variant with evidence of TP53 copy number loss or cnLOH | |
| MDS, morphologically defined: | ||||
| MDS with low blasts (MDS-LB) | <5% BM and <2% PB | |||
| MDS, hypoplasticc (MDS-h) | ||||
| MDS with increased blasts (MDS-IB): | ||||
| MDS-IB1 | 5%–9% BM or 2%–4% PB | |||
| MDS-IB2 | 10%–19% BM or 5%–19% PB or Auer rods | |||
| MDS with fibrosis (MDS-f) | 5%–19% BM; 2%–19% PB | |||
| Childhood MDS (cMDS): | ||||
| cMDS with low blasts (cMDS-LB): | ||||
| cMDS-LB, hypoplastic | <5% BM and <2% PB | |||
| cMDS-LB, not otherwise specified | ||||
| cMDS with increased blasts (cMDS-IB) | 5%–19% BM and 2%–19% PB | |||
| BM = bone marrow; cnLOH = copy neutral loss of heterozygosity; PB = peripheral blood. | ||||
| aCredit: Adapted from Khoury, J.D., Solary, E., Abla, O. et al. The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms. Leukemia 36, 1703–1719 (2022). https://doi | ||||
| bDetection of ≥15% ring sideroblasts may substitute for SF3B1 variant. Acceptable related terminology: MDS with low blasts and ring sideroblasts. | ||||
| cBy definition, ≤25% bone marrow cellularity, age adjusted. | ||||
From: Childhood Myelodysplastic Neoplasms Treatment (PDQ®)
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