Myelodysplastic syndrome
- Ineffective hematopoiesis
- Pre-leukemic (AML), defined as < 20 % blasts
- Common clinical picture: high MCV + elderly
- Cellular picture: pancytopenia, dysplastic cells, hypercellular
- Treatment: monitor progression, TNF inhibitors (lenalidomide)
Myeloproliferative disorders
- Essential thrombosis and polycythemia
- Essential thrombosis
- JAK2/MPL mutation
- Overproduction of megakaryocytes and platelets
- Can progress to myelofibrosis
- Common clinical picture: ischemia, stroke, ACS, clots
- Paradoxical bleeding – depletion of vWF
- Treatment:
- Low risk – aspirin
- Medium risk: hydroxyurea
- High Risk: pheresis
- Polycythemia
- JAK2 mutation –> erythrocytes divide in the absence of EPO
- Can progress to myelofibrosis
- Common clinical picture: fatigue, dizziness, increased sweating, red facial complexion, blurred vision, splenomegaly, uric acid from high RBC turnover and increased risk of blood clot
- Treatment: phlebotomy (blood letting), aspirin, hydroxyurea
Myelofibrosis
- Replacement of hematopoeitic stem stem cells with collagen
- Primary myelofibrosis
- JAK2/MPL mutation
- Over production of megakaryocytes
- Megakaryocytes overproduce FGF (cytokine)
- FGF activates fibroblasts
- Fibroblasts deposit collagen
- Secondary myelofibrosis
- Progression from ET or polycythemia
- Cellular picture: hypocellular (“dry tap” during a bone marrow aspirate)
- Treatment: supportive measures (transfusions) and HCT