Essential thrombocythaemia

Keywords: Thrombocythaemia

Key Information

Appropriate Tests

 

Essential thrombocythaemia (ET) is a myeloproliferative neoplasm in which the haemopoietic stem cell proliferation leads to a predominant increase in platelet count.

Full blood count, Blood film; Bone marrow biopsy, aspiration and trephine.

JAK-2 mutation may be positive in 50% of patients with ET. Calreticulin (CALR) mutations have been reported in up to 67% of patients with non-mutated JAK-2. 

Other tests may be useful to exclude non-ET myeloproliferative neoplasms.

See also Myeloproliferative neoplasms

Features

 

Thrombocytosis

 

Splenomegaly

 

Splenic infarction

 

Thrombosis (arterial and venous)

 

Bleeding

May be from a local lesion. 

  • Platelet dysfunction

Variable abnormalities of platelet function have been described. The skin bleeding time does not predict spontaneous or surgical bleeding and is not indicated.

  • Acquired von Willebrand disease

See von Willebrand disease

Cytotoxic therapy 

 

Disease progression/transformation

 

Anaemia, especially

  • Iron deficiency
 

Disease progression or transformation to:

 

  • Primary myelofibrosis

 

  • Acute leukaemia