Myeloproliferative neoplasms: changes since the WHO 2016 classification

A group of international experts, including haematopathologists, oncologists, and geneticists met on September 2021 in Chicago, IL, USA to update the 2016/17 World Health Organization classification system for haematopoietic tumours. After careful deliberation, introduced new International Consensus Classification (ICC) Myeloid Neoplasms Acute Leukaemias. The was published June 2022 (Arber DA, Orazi A, Hasserjian RP, et al. Blood 2022; 140: 1200–1228). This presentation focuses ICC-2022 category chronic myeloid leukaemia (CML), BCR::ABL1 positive negative myeloproliferative neoplasms (MPNs): essential thrombocythemia, polycythemia vera, primary myelofibrosis, MPN, unclassifiable. In CML, ICC recognises three disease phases: (CP), accelerated (AP), blast (BP) phase. Their definition has been streamlined. For MPN group, chose preserve role bone marrow morphology diagnostics, while also acknowledging complementary genetic markers establishing clonality, facilitating subtype designation, prognostication. Chronic neutrophilic (CNL) can now be diagnosed with a WBC > 13x 109/L. diagnosis eosinophilic leukaemia, NOS, requires showing dysplastic changes. Reference 1. Thiele J, Kvasnicka HM, consensus acute leukemias: neoplasms. Am J Hematol doi: 10.1002/ajh.26751. Epub ahead print. PMID: 36200127.