Idiopathic myelofibrosis is a clonal haematopoietic stem cell disorder in which there is increased bone marrow fibrosis. This causes extramedullary haematopoiesis, ie blood cell production in alternate sites such as the spleen/liver.
Presentation:
- Fatigue
- Weight loss
- Night sweats
- Low grade fever
- Splenomegaly
- Bleeding
- Complications of extramedullary haematopoiesis
- Pleural effusion
- Spinal cord compression
- Pulmonary hypertension
- Cardiac tamponade
Investigations
- Bloods
- Normochronic anaemia, Teardrop cells
- Thrombocytopaenia with large abnormal platelets or thrombocytosis
- Leucoerythroblastic cells (=immature red and white cells)
- Bone marrow
- ‘Dry tap’ on aspiration
- Biopsy shows increased fibrous tissue and megakaryocytes
- JAK2 in 50%
Treatment
- Supportive – transfusions
- Splenectomy
- Only chance of cure is with allogenic stem cell transplantation
Prognosis: poor – median survival less than 5 years.
Secondary myelofibrosis – this is a reaction to a disease rather than a clonal myeloproliferative disorder. Causes of secondary myelofibrosis include myeloma, metastatic carcinoma and TB.
