title: Essential thrombocythaemia.
abstract: Essential thrombocythaemia is a myeloproliferative disorder that results from the transformation of a multipotent haematopoietic progenitor. Its diagnosis can be challenging and its optimal management has been controversial, largely because of a virtual absence of randomised trials. However, this situation will be dramatically altered by two recent developments. First, the Medical Research Council Primary Thrombocythaemia 1 (PT-1) trial-the largest and most comprehensive randomised study of any myeloproliferative disorder-provides clear guidance on the management of patients with high-risk essential thrombocythaemia. Second, identification of a unique JAK2 mutation in a substantial proportion of patients with essential thrombocythaemia (and also other myeloproliferative disorders) has resulted in a powerful diagnostic tool and is likely to alter approaches to both the classification and management of the myeloproliferative disorders.
authors.affiliation: Department of Haematology, Guy's and St Thomas, NHS Foundation Trust, Lanbeth Palace Road, London SE1 7EH, UK.
authors.forename: Claire N
authors.initials: CN
authors.lastname: Harrison
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Green
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D013920:Thrombocythemia, Essential / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology