- Clonal proliferation of pleuripotent stem cells that release cytokines, causing BM fibrosis
- Sometimes polycythemia vera, essential thrombocytosis first
- Can evolve into AML
- Average age 67 (17% present at age < 50)
- History polycythemia vera or essential thrombocytosis
- Night sweats
- Weight loss
- Fever
- Generalized fatigue
- Sob, doe→ from anemia
- Abdominal discomfort, early satiety from hepato-splenomegaly→ sites of extra medullary hematopoeisis
- Thrombotic events: portal vein thrombosis, DVT, PE
- Often elevated WBCs, sometimes w/blasts; as develop BM failure--> anemia
- Often + JAK2 mutation
- Bone marrow bx to make dx