文摘
Essential thrombocythemia (ET) is an entity of chronic myeloproliferative neoplasms (MPN) with onset in old age. A diagnosis by exclusion is based on molecular and non-molecular criteria. Platelet count, bone marrow histology and Janus kinase2 (JAK 2) status are required for diagnosis confirmation (WHO criteria). Complex disorders of platelet and hemorheological function and the JAK 2 mutation dominate the variable disease with thrombotic and hemorrhagic complications. Age, platelet count and thrombotic/hemorrhagic events represent high risk criteria. The use of anagrelide (cytoreductive) needs cardiac risk assessment and monitoring due to potential cardiac side effects.