Atypical chronic myelogenous leukemia (aCML), BCR/ABL1 negative is a rare disorder classified into the category of myelodysplastic/myeloproliferative neoplasms (MDS/MPN), according to the 2016 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. It is, by definition, a BCR-ABL1-negative clonal disorder sharing myelodysplastic and myeloproliferative features.
Myeloid
Accelerated Phase Criteria for Chronic Myeloid Leukemia (CML)
The chronic myeloid leukemia (CML) is classically staged into chronic phase (CP, most patients at presentation), accelerated phase (AP) and blast phase (BP). Many definitions have been used for these stages, but all the data generated from the tyrosine kinase inhibitor (TKI) studies has used the historically standard definition where AP is defined by the presence of one or more of the following: ≥15% blasts in PB/BM, ≥20% basophils in PB, platelets <100,000/µL unrelated to treatment or the development of cytogenetic evolution. Blast phase is defined by the presence of ≥30% blasts in the peripheral blood or bone marrow, the presence of clusters of blasts in marrow or the presence of extramedullary disease with immature cells (i.e., a myeloid sarcoma).
Diagnostic Criteria for Myeloid Neoplasms with Myelodysplasia
Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by clonal proliferation of hematopoietic stem cells, recurrent genetic abnormalities, myelodysplasia, ineffective hematopoiesis, peripheral-blood cytopenia, and a high risk of evolution to acute myeloid leukemia (AML).