Table 8

Diagnostic criteria for myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) [5].

- Anemia associated with erythroid-lineage dysplasia, with or without multilineage dysplasia; ≥15% ring sideroblasts^a), <1% blasts in the peripheral blood, and <5% blasts in the bone marrow

- Persistent thrombocytosis, with platelet count ≥450×10⁹/L

- 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^b)

- No BCR-ABL1 fusion; no rearrangement of PDGFRA, PDGFRB or FGFR1; no PCM1-JAK2and no t(3;3)(q21.3;q26.2), inv(3)(q21.3q26.2), or del(5q)^c)

- No history of myeloproliferative neoplasm, myelodysplastic syndrome (except myelodysplastic syndrome with ring sideroblasts), or other myelodysplastic/myeloproliferative neoplasm

^a)≥15% ring sideroblasts is a required criterion even if SF3B1 mutation is detected. ^b)The diagnosis of myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis is strongly supported by the presence of SF3B1 mutation together with a JAK2 V617F, CALR, or MPL mutation. ^c)In a case that otherwise meets the diagnostic criteria for myelodysplastic syndrome with isolated del(5q).

Blood Res 2021;56:S51~S64 https://doi.org/10.5045/br.2021.2021010