Diagnostic criteria for myelodysplastic/myeloproliferative neoplasm, not otherwise specified (MDS/MPN, NOS)
| Myeloid neoplasm with mixed myeloproliferative and myelodysplastic features, not meeting the criteria for any other MDS/MPN, MDS, MPN* |
| Cytopenia (thresholds same as for MDS) |
| Blasts < 20% of the cells in blood and bone marrow |
| A platelet count of ≥ 450 × 109/L and/or a white blood cell count of ≥ 13 × 109/L |
| Presence of clonality: demonstration of a clonal cytogenetic abnormality and/or somatic mutation(s). If clonality cannot be determined, the findings have persisted and all other causes (eg, history of cytotoxic or growth factor therapy or other primary cause that could explain the myelodysplastic/myeloproliferative features) have been excluded. |
| No BCR::ABL1 or genetic abnormalities of myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions; no t(3;3)(q21.3;q26.2), inv(3)(q21.3q26.2),† or del(5q)‡ |
| Myeloid neoplasm with mixed myeloproliferative and myelodysplastic features, not meeting the criteria for any other MDS/MPN, MDS, MPN* |
| Cytopenia (thresholds same as for MDS) |
| Blasts < 20% of the cells in blood and bone marrow |
| A platelet count of ≥ 450 × 109/L and/or a white blood cell count of ≥ 13 × 109/L |
| Presence of clonality: demonstration of a clonal cytogenetic abnormality and/or somatic mutation(s). If clonality cannot be determined, the findings have persisted and all other causes (eg, history of cytotoxic or growth factor therapy or other primary cause that could explain the myelodysplastic/myeloproliferative features) have been excluded. |
| No BCR::ABL1 or genetic abnormalities of myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions; no t(3;3)(q21.3;q26.2), inv(3)(q21.3q26.2),† or del(5q)‡ |
MPNs, in particular those in accelerated phase and/or in post–PV or post–ET myelofibrotic stage, may simulate MDS/MPN, NOS. A history of MPN and/or the presence of MPN-associated mutations (in JAK2, CALR, or MPL) particularly if associated with a high VAF, tend to exclude a diagnosis of MDS/MPN, NOS. The presence of hypereosinophilia would favor a diagnosis of CEL, NOS.
In a case that otherwise meets criteria for MDS-NOS.
In a case that otherwise meets the diagnostic criteria for MDS with isolated del(5q).