Essential thrombocythemia: a hypercoagulable state.

Essential thrombocythemia is an entity characterized by clonal proliferation of megakaryocytes and thrombocytosis. We have analyzed the presenting manifestation of 13 patients with Essential Thrombocythemia diagnosed in the last three years. The major findings include the frequent presence of symptomatology of a hypercoagulable state with prompt improvement of these symptoms once the thrombocytosis is controlled. Constitutional symptoms, organomegaly, modest Leukocytosis and eosinophilia were also often seen. No catastrophic events were detected with a mean follow up period of 17.5 months.