Essential thrombocythemia (ET) is an indolent myeloproliferative neoplasm that
may be complicated by vascular events, including both thrombosis and bleeding.
This disorder may also transform into more aggressive myeloid neoplasms, in
particular into myelofibrosis. The identification of somatic mutations of JAK2,
CALR, or MPL, found in about 90% of patients, has considerably improved the
diagnostic approach to this disorder.
Genomic profiling also holds the potential to improve prognostication and, more
generally, clinical decision-making because the different driver mutations are
associated with distinct clinical features.
Prevention of vascular events has been so far the main objective of therapy, and
continues to be extremely important in the management of patients with ET. Lowdose
aspirin and cytoreductive drugs can be administered to this purpose, with cytoreductive treatment being primarily given to patients at high risk of vascular complications. Currently used cytoreductive drugs include hydroxyurea, mainly used in older patients, and interferon a, primarily given to younger patients. There is a need for disease-modifying drugs that can eradicate clonal hematopoiesis and/ or prevent progression to more aggressive myeloid neoplasms, especially in younger patients. In this article, we use a case-based discussion format to illustrate our approach to diagnosis and treatment of ET. (Blood. 2016;128(20):2403-2414)

BLOOD, 17 NOVEMBER 2016 x VOLUME 128, NUMBER 20