Essential Thrombocythemia Flashcards
1
Q
what is essential thrombocythemia?
A
a clonal hematopoietic stem cell disorder that causes increased platelet production
2
Q
what is the aetiology of essential thrombocythemia?
A
- JAK 2 V617F
- CALR
- MPL
3
Q
what may thrombocythemia lead to?
A
- microvascular occlusion
- large vessel thrombosis
- bleeding
4
Q
what symptoms can be caused by microvascular occlusions?
A
microvascular occlusions involve small vessels in the:
- distal extremities: erythromelalgia
- eye: ocular migraine
- CNS: TIAs
5
Q
why does extreme thrombocytosis increase the risk of bleeding?
A
- due to an acquired deficiency of von willebrand factor
- platelets adsorb and proteolyze high molecular weight von willebrand multimers, leading to type 2 acquired von willebrand syndrome
6
Q
what are the symptoms of essential thrombocythemia?
A
- bruising
- bleeding (e.g. epistaxis)
- ocular migraine
- erythromelalgia
- neurological deficit (e.g. TIA)
7
Q
what are the investigations for essential thrombocythemia?
A
- FBC
- blood film
- iron studies
- cytogenetic studies
- JAK 2 V617F/CALR/MPL mutational analysis
- BCR-ABL assay (e.g. to exclude CML)
- ? bone marrow biopsy
8
Q
what is the management of essential thrombocythemia?
A
- cytoreductive therapy (e.g. hydroxyurea, anagrelide, interferon-alpha)
- aspirin (81mg)
