Essential thrombocythaemia

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm characterized by an expansion of the megakaryocytic lineage, leading to an isolated elevation of platelets. It increases the risk of both thrombosis and hemorrhage. 

The disease has traditionally been a diagnosis of exclusion, requiring the absence of reactive conditions and other clonal disorders that may present with thrombocytosis. The discovery of mutations in JAK2 and MPL now allows for the positive identification of ET in more than one-half of all cases. 

Diagnosis is often when there is an "unexplained and persistent thrombocytosis" (platelet count > 450 × 109/L). Several diagnostic criteria have been put forward, e.g. WHO 2008 and BCSH 2010 2.

Can be variable depending on the organ involved and usually suspected when there are thrombosis of various vessels or ischemic events such as recurrent strokes.

Share article

Article information

rID: 45109
System: Haematology
Tag: cases, cases
Synonyms or Alternate Spellings:
  • Essential thrombocytosis
  • Essential thrombocythemia
  • Essential thrombocythaemia (ET)

Support Radiopaedia and see fewer ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.