hematology and oncology
Essential Thrombocythemia
Key Points
Essential thrombocythemia is a clonal abnormality of a multipotent hematopoietic stem cell resulting in increased platelets. Patients are at risk of microvascular thrombosis and hemorrhage. Essential thrombocythemia is a diagnosis of exclusion; in particular, other myeloproliferative neoplasms and reactive (secondary) thrombocytosis must be ruled out. Patients without symptoms require no therapy.Aspirinis usually effective for microvascular events (ocular migraine, erythromelalgia and transient ischemic attacks). Patients with extreme thrombocytosis may require more aggressive treatment to control the platelet count; such measures include pegylated interferon alpha,hydroxyurea,anagrelide,ruxolitinib, and plateletpheresis. 