Essential thrombocythemia: A review of diagnostic and pathologic features

Steven Sanchez, April A. Ewton

Research output: Contribution to journalReview articlepeer-review

28 Scopus citations


Context. - Essential thrombocythemia (ET) is a chronic myeloproliferative disorder (CMPD) characterized predominately by thrombocytosis and abnormal megakaryocyte proliferation. The current diagnostic criteria require a combination of clinical, histologic, and cytogenetic data. The diagnosis relies largely on exclusion of other causes of thrombocytosis. Objective. - Describe historical, clinical, and laboratory features of ET in order to understand, clarify, and more accurately diagnose this entity. Data Sources. - Review contemporary and historical literature on ET and other causes of thrombocytosis. Conclusions. - ET is a relatively indolent and often asymptomatic CMPD that is characterized primarily by a sustained elevation in platelets ≥600 × 103/mL (≥600 × 109/L), proliferating enlarged and hyperlobated megakaryocytes, and minimal to absent bone marrow fibrosis. Significant changes and revisions to the diagnostic requirements and criteria for ET have occurred during the last 30 years. Recently, a mutation in the Janus kinase 2 (JAK2) gene has been found in a significant number of cases of ET and other CMPDs. In up to 57% of ET cases, a mutation in the JAK2 gene can be detected. In the absence of a JAK2 mutation and features of another CMPD, the diagnosis of ET remains a diagnosis of exclusion after other causes of thrombocytosis have been excluded.

Original languageEnglish (US)
Pages (from-to)1144-1150
Number of pages7
JournalArchives of Pathology and Laboratory Medicine
Issue number8
StatePublished - Aug 1 2006

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Medical Laboratory Technology


Dive into the research topics of 'Essential thrombocythemia: A review of diagnostic and pathologic features'. Together they form a unique fingerprint.

Cite this