Overview

Myeloproliferative Disoders ⇒ chronic myeloid leukaemia, polycythaemia vera, essential thrombocytosis, primary myelofibrosis

• Essential Thrombocytosis (aka Primary Thrombocythaemia) → chronic myeloproliferative disorder associated with sustained dysregulated megakaryocyte proliferation in the bone marrow, increasing the number of circulating platelets causing thrombocytosis

• Average age at diagnosis is 50-70 years old

• JAK2 mutation is found in around 50% of patients

• MYELOFIBROSIS → progressive bone marrow fibrosis (causes bone marrow failure)

  • Massive splenomegaly

  • Pancytopenia

  • Dry Tap ⇒ failure of bone marrow aspirate

  • Tear Drop poikilocytes (dactrocytes) on blood film → flat, elongated RBC’s

    <aside> 💡 CML and Myelofibrosis ⇒ main conditions with MASSIVE splenomegaly

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Making Diagnosis

Clinical Features:

• Erythromelalgia → burning pain and dusky congestion of the extremities. Pain increases with heat and improves with cold.
• Splenomegaly
• Arterial and Venous Thrombosis
• Bleeding

Investigations:

• FBC → platelet count ≥450 x 10⁹/L
• JAK2 Mutation Testing