Polycythemia vera and essential thrombocythemia: 2013 update on diagnosis, risk‐stratification, and management

Disease OverviewPolycythemia Vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) primarily characterized by erythrocytosis and thrombocytosis, respectively. Other disease features include leukocytosis, splenomegaly, thrombohemorrhagic complications, vasomotor disturbances, pruritus and a small risk of disease progression into acute myeloid leukemia or myelofibrosis. DiagnosisAlmost all patients with PV harbor a JAK2 mutation. When PV is suspected, the presence of a JAK2 mutation highly suggests the diagnosis and its absence, combined with normal or increased serum erythropoietin level, excludes the diagnosis. Differential diagnosis of ET should include reactive thrombocytosis, chronic myeloid leukemia, prefibrotic myelofibrosis and RARS‐T (refractory anemia with ring sideroblasts associated with marked thrombocytosis). A JAK2 mutation is found in 50–70% of patients with ET, myelofibrosis or RARS‐T and is capable of distinguishing reactive from clonal thrombocytosis. Risk StratificationCurrent risk stratification in PV and ET is designed to estimate the likelihood of thrombotic complications: high‐risk is defined by the presence of age >60 years or presence of thrombosis history; low‐risk is defined by the absence of both of these two risk factors. Recent data considers JAK2V617F and cardiovascular (CV) risk factors as additional risk factors for thrombosis. Presence of extreme thrombocytosis (platelet count >1,000 × 109/L) migh...
Source: American Journal of Hematology - Category: Hematology Authors: Tags: Annual Clinical Updates in Hematological Malignancies: A Continuing Medical Education Series Source Type: research