Clonal stem‑cell disorders causing excess proliferation of one or more myeloid lineages (RBCs, WBCs, platelets). Often associated with JAK2 V617F mutation (except CML → BCR‑ABL)
| Disorder | Main Cell Line | Hallmark Findings | Key Mutation | Notes |
|---|---|---|---|---|
| Polycythaemia vera (PV) | RBCs | ↑ Hb/Hct, pruritus after hot bath, plethora, splenomegaly | JAK2+ | Erythropoietin ↓ |
| Essential thrombocythaemia (ET) | Platelets | Persistent thrombocytosis (>450 ×10⁹/L), microvascular symptoms (erythromelalgia, headache), splenomegaly | JAK2+ (50–60%), CALR/MPL | Risk of thrombosis & bleeding |
| Primary myelofibrosis (PMF) | Fibroblast activation → marrow fibrosis | Leukoerythroblastic blood film, tear‑drop RBCs, massive splenomegaly | JAK2+ (50%), CALR/MPL | “Dry tap” on marrow aspirate |
| Chronic myeloid leukaemia (CML) | Granulocytes | Marked leukocytosis, basophilia, splenomegaly | BCR‑ABL (Philadelphia chromosome) | Responds to imatinib |
| Disorder | First‑line | Additional |
|---|---|---|
| PV | Venesection ± hydroxycarbamide | Aspirin for thrombosis prevention |
| ET | Hydroxycarbamide (high‑risk) | Aspirin (low‑risk) |
| PMF | Supportive, ruxolitinib (JAK inhibitor) | Stem‑cell transplant (young fit) |
| CML | Imatinib (tyrosine kinase inhibitor) | Alternatives: dasatinib, nilotinib |
Myeloproliferative neoplasms (MPN)
The most clinically relevant MPN include chronic myeloid leukemia (CML), polycythemia vera (PV), primary myelofibrosis (PMF), and essential thrombocythemia (ET).
Chronic eosinophilic leukemia is also a type of MPN.
All myeloproliferative neoplasms may lead to elevated uric acid levels and gout as a result of increased cellular breakdown. They are also associated with an increased risk of acute myeloid leukemia.
Chronic Myelogenous Leukemia (CML)
Polycythemia Vera
Agnogenic Myeloid Metaplasia
Tx
Allogenic hematopoietic cell transplantation (allo-HCT) for patients under 60 yo age
Palliative treatment - Median survival time is 13 months for patients who are