essential thrombocythemia
Also written as: ET — essential thrombocythemia
A myeloproliferative neoplasm characterized by persistent elevation of platelet counts and megakaryocyte hyperplasia in the bone marrow.
Full Definition
Essential thrombocythemia is a clonal hematopoietic stem cell disorder characterized by sustained thrombocytosis and increased megakaryocyte numbers in the bone marrow. The diagnosis requires exclusion of other causes of thrombocytosis and other myeloproliferative neoplasms. Most patients harbor mutations in JAK2, CALR, or MPL genes. Clinical manifestations may include thrombotic or hemorrhagic complications, though many patients remain asymptomatic. The disease has a relatively indolent course but may transform to myelofibrosis or acute leukemia. Treatment is risk-adapted, focusing on preventing thrombotic complications through platelet reduction in high-risk patients.
Usage
Usage note: Distinguish from reactive thrombocytosis, which has an identifiable underlying cause.
In Context
- "The patient's sustained platelet elevation led to a diagnosis of essential thrombocythemia." — hematology consultation
- "Hydroxyurea was initiated for essential thrombocythemia given the patient's high thrombotic risk." — treatment plan