Table 3 Classification and defining features of myelodysplastic neoplasms (MDS).

From: The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms

 

Blasts

Cytogenetics

Mutations

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 mutationa (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 mutations, or 1 mutation with evidence of TP53 copy number loss or cnLOH

MDS, morphologically defined

   

 MDS with low blasts (MDS-LB)

<5% BM and <2% PB

  

 MDS, hypoplasticb (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

  
  1. aDetection of ≥15% ring sideroblasts may substitute for SF3B1 mutation. Acceptable related terminology: MDS with low blasts and ring sideroblasts.
  2. bBy definition, ≤25% bone marrow cellularity, age adjusted.
  3. BM bone marrow, PB peripheral blood, cnLOH copy neutral loss of heterozygosity.
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