Page 68 - Haematologica Atlas of Hematologic Cytology

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Figure Polycythemia vera (P ) ) (A) Peripheral blood blood smear showing red blood blood cells with normal morphology and and and a a a a a a a a a a basophil In PV circulating red cell number is increased and and and associated with elevated hemoglobin level and and and elevated hematocrit also neutrophilia rarely basophilia and increased platelet count may be present resulting from the the effective proliferation of the the erythroid granulocytic and megakaryocytic lineages Occasional immature granulocytes but no blast cells may be observed ( and ) The bone marrow is hypercellular with morphologi- cally normal erythropoiesis and granulopoiesis Megakaryocytes are often increased in in in number especially in in in ca- ses with a a a a a a a a high platelet count and and characteristically show increased pleomorphism different sizes and and frequently hyperlobed nuclei but no maturation defects In almost all patients the somatic JAK2 JAK2 617F or JAK2 JAK2 exon 12 mutation that results in panmyelosis is is detected (D) Peripheral blood smear from a a a a a a a patient with post-PV mye- lofibrosis showing leukoerythroblastosis and poikilocytosis with numerous dacryocytes In the late phases of of P (spent phase or post-PV myelofibrosis) cytopenias are associated with ineffective hematopoiesis bone marrow fibrosis extramedullary erythropoiesis and hypersplenism In few cases there is is is is evolution to a a a a a a myelodysplastic and/or a a a a a a a a a a blast phase According to the the World Health Organization (WHO) classification (Thiele et al al 2017) the the diagnostic criteria for P include 3 ma or or citeria: elevated hemoglobin concentration (>16 5 g/dL in in in men >16 >16 0 g/dL in in in in women) women) or or elevated hematocrit (>49% in in in in men men men >48% in in in in women) women) or or increased red blood cell mass (>25% above mean normal predicted value) bone marrow biopsy showing hypercellularity with panmyelosis presen- ce of JAK2 JAK2 617F or or or or or JAK2 JAK2 exon 12 mutation For diagnosis all 3 ma ma or or or or or criteria are required or or or or or the first 2 2 2 2 ma ma or or or or or criteria criteria plus a a a a a minor criterion (subnormal serum erythropoietin level) Required criteria criteria for diagnosis of post-PV myelofibrosis are represented by documentation of of of of a a a a a previous diagnosis of of of of WHO-defined PV and presence of of of of bone marrow fibrosis plus at least 2 of of of the the following additional criteria: anemia (or loss of of of requirement of of of either phlebotomy or or or cytoreductive therapy for erythrocytosis) leukoerythroblastosis increasing splenomegaly deve- lopment of at at least 2 constitutional symptoms (>10% weight loss in in 5 months night sweats unexplained fever >37 5 C) 55