PVSG and WHO vs European Clinical, Molecular and Pathological Criteria for prefibrotic myeloproliferative neoplasms

Figure 1 The concept of Dameshek in 1950 on polycythemia vera as a trilinear myeloproliferative disorder due to an unknown excessive bone marrow stimulating factor and/or a lack or a diminution in the normal inhibitory factor, which appeared to be caused by the acquired heterozygous and/or homozygous JAK2^V617F mutation discovered by James et al[5]. The unifying concept of Dameshek in 1951 on lumping the chronic disorders [myeloproliferative disorder (MPDs)] essential thrombocythemia (ET), polycythemia vera (PV), agnogenic myeloid metaplasia (AMM) has been broken up by the Polycythemia Vera Study Group (PVSG) in 1975 into Ph-positive (Ph⁺) thrombocythemia and chronic myeloid leukemia (CML) and the Ph-negative MPDs ET, PV and myelofibrosis (MF). In 2005, PV indeed proved to be a JAK2^V617F mutated trilinear MPD, whereas ET and PMF are either positive or negative for the JAK2^V617F mutation. PMGM: Primary megakaryocytic and granulocytic myeloproliferation; MPN: Myeloproliferative neoplasm; WHO: World Health Organization; ECP: European Clinical and Pathologic; ECMP: European Clinical, Molecular and Pathological; MGM: Megakaryocytic, granulocytic myeloproliferation.