Table 13

Diagnostic criteria for MDS/MPN with ring sideroblasts and thrombocytosis

MDS/MPN diagnostic criteria
• Anemia associated with erythroid lineage dysplasia with or without multilineage dysplasia, ≥15% ring sideroblasts,* <1% blasts in PB and <5% blasts in the BM
• Persistent thrombocytosis with platelet count ≥450 × 109/L
• Presence of a SF3B1 mutation or, in the absence of SF3B1 mutation, no history of recent cytotoxic or growth factor therapy that could explain the myelodysplastic/myeloproliferative features
• No BCR-ABL1 fusion gene, no rearrangement of PDGFRA, PDGFRB, or FGFR1; or PCM1-JAK2; no (3;3)(q21;q26), inv(3)(q21q26) or del(5q)
• No preceding history of MPN, MDS (except MDS-RS), or other type of MDS/MPN
  • * At least 15% ring sideroblasts required even if SF3B1 mutation is detected.

  • A diagnosis of MDS/MPN-RS-T is strongly supported by the presence of SF3B1 mutation together with a mutation in JAK2 V617F, CALR, or MPL genes.

  • In a case which otherwise fulfills the diagnostic criteria for MDS with isolated del(5q)-no or minimal absolute basophilia; basophils usually <2% of leukocytes.