Myelofibrosis is a rare type of chronic leukaemia, subclassed as a type of myeloproliferative disease.
- Marrow fibrosis and splenomegaly, de novo or following transformation of PV or ET
- Usually >50 years old
- Abnormal megkaryocytes produced in increased numbers.
- PDGF and TGFβ are released by megakaryocytes, stimulating fibrosis.
- Haematopoietic stem cells move to the spleen and liver
- Presentation: fatigue, weight loss, splenomegaly, splenic pain, portal hypertension, bleeding varices, ascites and hepatomegaly
- Anaemia and tear-drop poikilocytes (abnormally shaped RBCs)
- Initially thrombocytosis and neutrophilia, in advanced disease these fall
- Bone marrow: aspiration gives dry tap, trephine shows dense reticulin fibres, fibrosis and osteosclerosis
- JAK2 mutation seen in 40%
- Average survival 5-7 years, leukaemic transformation in 15%
- Asymptomatic cases may require no treatment
- Anaemia treated with corticosteroid, androgen or EPO – transfusion usually required
- Hydroxycarbamide reduces symptoms and splenomegaly
- Thalidomide: counter abnormal marrow angiogenesis
- Splenic irradiation and splenectomy may be considered
- Allogenic SCT potentially curative, limited to rare, young patients
