Copyright ©The Author(s) 2015.
World J Hematol. Aug 6, 2015; 4(3): 16-53
Published online Aug 6, 2015. doi: 10.5315/wjh.v4.i3.16
Table 9 2015 WHO Clinical Molecular and Pathological criteria for the diagnosis of normocelular essential thrombocythemia carrying one of the MPL515 mutations[78]
CM JAK2 wild type ETBone marrow pathology (P) criteria (WHO)
(1) Platelet count > 350 × 109/L and presence of large platelets in blood smearP1 Proliferation of large to giant mature megakaryocyte with hyperlobulated, staghorn-like nuclei in a normocellular bone marrow (< 65%)
(2) Hemoglobin, haematocrit and erythrocyte count in the normal rangeNo increase of erythropoiesis, and no increase or immaturity of granulopoiesis or erythropoiesis, no or slight increase in reticulin RF 0/1
(3) Presence of MPL515 mutation and JAK2 wild typeET → MF
(4) Normal serum EPOIncreased reticulin fibrosis around dense clustered megakaryocytes in a normocellular bone marrow and reduced erythropoiesis. Follow-up data of RF and MF related to splenomegaly in MPL515 ET transltional states to MF are lacking. Grading of RF and MF similar as described for PV
(5) Normal LAP score and CD11b expression
(6) No or slight splenomegaly
(7) No leukoerythroblastosis
(8) No preceding or allied CML, PV, RAS-T or MDS