[Diagnosis and treatment of essential thrombocythemia].

Essential thrombocythemia (ET) is one of the chronic myeloproliferative disorders (MPD), clonal disorders of hematopoietic stem cell. The differential diagnosis from the other MPD and reactive thrombocytosis was described. The treatment of this disease was then stated with emphasis on the importance of control of platelet count. For the control, drugs to suppress the megakaryocytic proliferation are used, including busulfan, hydroxyurea, interferon-alpha and Anagrelide. The therapy for asymptomatic patients and pregnant women as well as patients with acute hemorrhage and thrombosis was also discussed.