<prompt> Which of the following is not compatible with a diagnosis of chronic myelomonocytic leukemia?Peripheral blood monocytosis more than 1 x 109LAbsence of Philadelphia chromosomeMore than 20 blasts in blood or bone marrowMyelodysplasia  <response>: WHO 2017 Diagnostic criteria of CMML: Persistent peripheral blood monocytosis 1 x 109L with monocytes accounting for 10 of the leukocytes WHO criteria for BCR-ABL1--positive chronic myeloid leukaemia, primary myelofibrosis, polycythaemia vera and essential thrombocythaemia are not met No rearrangement of PDGFRA, PDGFRB or FGFR1 and no PCM1-JAK2 Blasts incl. promonocytes constitute 20 of the cells in the peripheral blood and bone marrow Dysplasia involving 1 myeloid lineages orIf myelodysplasia is absent or minimal, criteria 1-4 are met and:- an acquired, clonal cytogenetic or molecular genetic abnormality is present in haematopoietic cells, or- the monocytosis has persisted for 3 months and all other causes of monocytosis e.g. malignancy, infection, and inflammation have been excluded 