Myeloproliferative syndromes Flashcards
What is primary polycythaemia vera?
Increased red cell volume (due to clonal malignancy of marrow stem cell), usually high RBC (but other cell lines may be increased instead). Usually due to JAK2 mutation (95% cases)
What is the common genetic cause of primary polycythaemia vera?
JAK2 mutation
How do you evaluate polycythaemai?
If a patient has a high HCT:
o Apparent/relative if the plasma volume is also reduced
o Primary absolute polycythaemia if EPO is low or normal
o Secondary absolute polycythaemia if EPO is elevated
What is the prognosis of primary polycythaemia vera?
Median survival 10-16 years, death usually from cardiovascular events or thrombosis
What is the treatment of primary polycythaemia vera?
venesection (if HCT<0.45), aspirin, myelosupressive drugs (hydroxycarbamide, interferon, busulphan)
What is essential thrombocytopenia?
Sustained increase in platelet due to megakaryocyte proliferation, defined by a non-reactive thrombocythaemic state that isn’t accounted for by another myeloproliferative syndrome/neoplasm
How is essential thrombocytopenia diagnosed?
• mutation (JAK 2, CALR, MPL), bone marrow biopsy
o Exclude secondary causes – infection, inflammation, iron deficiency, haemorrhage, hyposplenism, malignancy, drugs e.g. steroids
How is essential thrombocytopenia treated?
Aspirin, higher risk patients may be given myelosuppressive drugs (hydroxycarbamide, anagrelide)
What is myelofibrosis?
• A stem cell malignancy, this is a progressive generalised reactive fibrosis of the bone marrow in association with haematopoiesis of the liver and spleen. The fibrosis is secondary to hyperplasia of abnormal megakaryocytes.
How would myelofibrosis appear on blood film and bone marrow?
o Blood film: teardrop poikilocytes and leucoerythroblastic
o Bone marrow: increased reitculin fibrosis, hypercellular and streaming
What’s the treatment and prognosis for myelofibrosis ?
- Treatment: transfusion, irradiation of spleen
* Prognosis: poor overall (<1-12 years)
