Myelofibrosis

Question 1

Define myelofibrosis

Answer 1

Disorder of haematopoietic stem cells characterised by progressive marrow fibrosis and
extramedullary haematopoiesis

Question 2

What are the causes/risk factors of myelofibrosis?

Answer 2

Abnormal megakaryocyte precursors release cytokines e.g. PDGF -> fibroblast proliferation -
> collagen deposition in bone marrow and extramedullary haematopoiesis

Primary – unknown aetiology

Secondary
• Leukaemia
• Hypoparathyroidism
• Drugs

Risk factors
• Industrial solvents e.g. benzene
• Radiation (higher incidence in
Hiroshima victims)

Question 3

What are the symptoms of myelofibrosis?

Answer 3

Hypercatabolic state
• Weight loss
• Night sweats
• Low-grade fever
• Cachexia
• Fatigue
• Pruritus

Splenomegaly
• Early satiety
• LUQ discomfort

Anaemia (ineffective erythropoiesis,
hypersplenism)
• Fatigue

Other
• Bleeding
• Bone pain
• Gout

Question 4

What are the signs of myelofibrosis?

Answer 4

• Splenomegaly

* Hepatomegaly

Question 5

What investigations are carried out for myelofibrosis?

Answer 5

• FBC - initially: Variable due to the massive spleen size.
- Then: Anaemia, leucopoenia and thrombocytopaenia
• Blood Smear - tear Drop Cells (Dacrocytes)
- Leukoerythroblastosis: WBC and RBC precursor cells in the blood –these include promyelocytes, myelocytes and metamyelocytes; as well as nucleated RBCs.
• Marrow Aspirate - unsuccessful due to fibrosis (dry marrow).
• Marrow Biopsy - fibrotic hypercellular marrow, with dense reticulin fibres on silver staining