WHO diagnostic criteria for aCML
| Diagnostic criteria . |
|---|
| • Peripheral blood leukocytosis (WBC count ≥13 × 109/L) because of increased numbers of neutrophils and their precursors with prominent dysgranulopoiesis |
| • Neutrophil precursors (promyelocytes, myelocytes, metamyelocytes) ≥10% of leukocytes |
| • No Ph chromosome or BCR-ABL1 fusion gene and not meeting criteria for PV, ET, or PMF* |
| • No evidence of PDGFRA, PDGFRB, FGFR1 rearrangement, or PCM1-JAK2 |
| • Minimal absolute basophilia; basophils usually <2% of leukocytes |
| • No or minimal absolute monocytosis; monocytes usually <10% of leukocytes |
| • Hypercellular bone marrow with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| • Less than 20% blasts in the blood and bone marrow |
| Diagnostic criteria . |
|---|
| • Peripheral blood leukocytosis (WBC count ≥13 × 109/L) because of increased numbers of neutrophils and their precursors with prominent dysgranulopoiesis |
| • Neutrophil precursors (promyelocytes, myelocytes, metamyelocytes) ≥10% of leukocytes |
| • No Ph chromosome or BCR-ABL1 fusion gene and not meeting criteria for PV, ET, or PMF* |
| • No evidence of PDGFRA, PDGFRB, FGFR1 rearrangement, or PCM1-JAK2 |
| • Minimal absolute basophilia; basophils usually <2% of leukocytes |
| • No or minimal absolute monocytosis; monocytes usually <10% of leukocytes |
| • Hypercellular bone marrow with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| • Less than 20% blasts in the blood and bone marrow |
ET, essential thrombocythemia; Ph, Philadelphia; PMF, primary myelofibrosis; PV, polycythemia vera; WBC, white blood cell.
Cases of myeloproliferative neoplasm (MPN), particularly those in accelerated phase and/or in postpolycythemic or postessential thrombocythemic myelofibrosis, if neutrophilic, may simulate aCML. A previous history of MPN, the presence of MPN features in the bone marrow and/or MPN-associated mutations (in JAK2, CALR, or MPL) tend to exclude a diagnosis of aCML. Conversely, a diagnosis of aCML is supported by the presence of SETBP1 and/or ETNK1 mutations. The presence of a CSF3R mutation is uncommon in aCML and, if detected, should prompt a careful morphologic review to exclude an alternative diagnosis of chronic neutrophilic leukemia or other myeloid neoplasm.1