Diagnostic criteria for atypical chronic myeloid leukemia
| World Health Organization criteria . | International Consensus Classification criteria . |
|---|---|
| PB leukocytosis (WBC count ≥13 × 109/L) because of increased numbers of neutrophils and their precursors with prominent dysgranulopoiesis | Leukocytosis ≥13 × 109/L, due to increased numbers of neutrophils and their precursors (promyelocytes, myelocytes, and metamyelocytes), the latter constituting ≥10% of the leukocytes |
| Neutrophil precursors (promyelocytes, myelocytes, metamyelocytes) ≥10% of leukocytes | Dysgranulopoiesis, including the presence of abnormal hyposegmented and/or hypersegmented neutrophils ± abnormal chromatin clumping |
| Cytopenia (anemia, hemoglobin <13 g/dL in males, <12 g/dL in females; neutropenia, absolute neutrophil count <1.8 × 109/L; thrombocytopenia, platelets <150 × 109/L) | |
| Less than 20% blasts in the PB and BM | Blasts <20% of the cells in PB and BM |
| No or minimal absolute monocytosis; monocytes usually <10% of leukocytes | No or minimal absolute monocytosis; monocytes constitute <10% of the PB leukocytes |
| Minimal absolute basophilia; basophils usually <2% of leukocytes | No eosinophilia; eosinophils constitute <10% of the PB leukocytes |
| Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages | Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| No Ph chromosome or BCR::ABL1 fusion gene and not meeting criteria for PV, ET, or PMF | No BCR::ABL1 or genetic abnormalities of M/L-Eo with TK gene fusions. The absence of MPN-associated driver mutations and the presence of SETBP1 mutations in association with ASXL1 provide additional support for a diagnosis of aCML. |
| No evidence of PDGFRA, PDGFRB, FGFR1 rearrangement, or PCM1::JAK2 |
| World Health Organization criteria . | International Consensus Classification criteria . |
|---|---|
| PB leukocytosis (WBC count ≥13 × 109/L) because of increased numbers of neutrophils and their precursors with prominent dysgranulopoiesis | Leukocytosis ≥13 × 109/L, due to increased numbers of neutrophils and their precursors (promyelocytes, myelocytes, and metamyelocytes), the latter constituting ≥10% of the leukocytes |
| Neutrophil precursors (promyelocytes, myelocytes, metamyelocytes) ≥10% of leukocytes | Dysgranulopoiesis, including the presence of abnormal hyposegmented and/or hypersegmented neutrophils ± abnormal chromatin clumping |
| Cytopenia (anemia, hemoglobin <13 g/dL in males, <12 g/dL in females; neutropenia, absolute neutrophil count <1.8 × 109/L; thrombocytopenia, platelets <150 × 109/L) | |
| Less than 20% blasts in the PB and BM | Blasts <20% of the cells in PB and BM |
| No or minimal absolute monocytosis; monocytes usually <10% of leukocytes | No or minimal absolute monocytosis; monocytes constitute <10% of the PB leukocytes |
| Minimal absolute basophilia; basophils usually <2% of leukocytes | No eosinophilia; eosinophils constitute <10% of the PB leukocytes |
| Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages | Hypercellular BM with granulocytic proliferation and granulocytic dysplasia, with or without dysplasia in the erythroid and megakaryocytic lineages |
| No Ph chromosome or BCR::ABL1 fusion gene and not meeting criteria for PV, ET, or PMF | No BCR::ABL1 or genetic abnormalities of M/L-Eo with TK gene fusions. The absence of MPN-associated driver mutations and the presence of SETBP1 mutations in association with ASXL1 provide additional support for a diagnosis of aCML. |
| No evidence of PDGFRA, PDGFRB, FGFR1 rearrangement, or PCM1::JAK2 |
BM, bone marrow; ET, essential thrombocythemia; M/L-Eo, myeloid/lymphoid neoplasms with eosinophilia; PB, peripheral blood; PMF, primary myelofibrosis; PV, polycythemia vera; TK, tyrosine kinase; WBC, white blood cell.