Diagnostic criteria for aCML, BCR-ABL1−
| aCML diagnostic criteria . |
|---|
| • PB leukocytosis due to increased numbers of neutrophils and their precursors (promyelocytes, myelocytes, metamyelocytes) comprising ≥10% of leukocytes) |
| • Dysgranulopoiesis, which may include abnormal chromatin clumping |
| • No or minimal absolute basophilia; basophils usually <2% of leukocytes |
| • No or minimal absolute monocytosis; monocytes <10% of leukocytes |
| • Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| • <20% blasts in the blood and BM |
| • No evidence of PDGFRA, PDGFRB, or FGFR1 rearrangement, or PCM1-JAK2 |
| • Not meeting WHO criteria for BCR-ABL1+ CML, PMF, PV, or ET* |
| aCML diagnostic criteria . |
|---|
| • PB leukocytosis due to increased numbers of neutrophils and their precursors (promyelocytes, myelocytes, metamyelocytes) comprising ≥10% of leukocytes) |
| • Dysgranulopoiesis, which may include abnormal chromatin clumping |
| • No or minimal absolute basophilia; basophils usually <2% of leukocytes |
| • No or minimal absolute monocytosis; monocytes <10% of leukocytes |
| • Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| • <20% blasts in the blood and BM |
| • No evidence of PDGFRA, PDGFRB, or FGFR1 rearrangement, or PCM1-JAK2 |
| • Not meeting WHO criteria for BCR-ABL1+ CML, PMF, PV, or ET* |
Cases of MPN, particularly those in accelerated phase and/or in post-polycythemic or post-essential thrombocythemic myelofibrosis, if neutrophilic, may simulate aCML. A previous history of MPN, the presence of MPN features in the BM 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 CNL or other myeloid neoplasm.