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

Figure 6 JAK2 wild type hypercellular essential thrombocythemia with platelet counts of 2180 × 10⁹/L, no splenomegaly, normal lactodehydrogenase and normal white blood cell differential counts with a characteristics picture of prefibrotic primary dysmegakaryocytic granulocytic myeloproliferation. A, B: JAK2 wild type hypercellular essential thrombocythemia with a typical primary megakaryocytic and granulocytic myeloproliferation bone marrow histology with the presence of abnormal clustering and increase in atypical giant to medium sized dysmorphic megakaryocytes containing bulky, clumsy (cloud-like) hypolobulated nuclei and definitive maturation defects; C: Reticulin fibrosis grade 0. Arrows indicate: Immature dysmorphic megakaryocytes with cloud-like nuclei.