Essential Thrombocythemia

Question 1

What is essential thrombocythemia?

Answer 1

Sustained Increased platelet count
A type of myeloproliferative disorder

Question 2

Causes of essential thrombocythemia?

Answer 2

JAK2 or CALR mutations
Continually active signal pathway
The haematopoietic cell matures into megakaryocyte and produces platelets

Question 3

What can essential thrombocythemia develop into?

Answer 3

Myelofibrosis
Acute leukaemia

Question 4

How does essential thrombocythemia present?

Answer 4

• Fatigue
• Headache
• Dizziness
• Nausea
• Tinnitus
• Numbness in hand & feet

Question 5

What investigations are done for essential thrombocythemia?

Answer 5

Genetic association with JAK2 and CALR
Megakaryocyte increased in bone marrow biopsy
WBC and RBC can be elevated

Question 6

Management of essential thrombocythemia?

Answer 6

hydroxyurea (hydroxycarbamide) is widely used to reduce the platelet count
interferon-α is also used in younger patients
low-dose aspirin may be used to reduce the thrombotic risk

Question 7

Risks of not treating (essential) thrombocythemia?

Answer 7

Raised platelets = increased risk of clots (DVT, PE, MI, stroke etc)
Sometimes bleeding disorders (excessive platelets use up all free von willebrand factor so clotting might not occur properly with injury)

Question 8

What differentials are there for essential thrombocythemia?

Answer 8

Iron deficiency
Inflammatory
Malignancy
Myelodysplasia