Myelofibrosis can occur secondary to other bone marrow conditions (polycythaemia vera, chronic myeloid leukaemia) or as a primary condition - idiopathic myelofibrosis.
Myelofibrosis (MF) is one of the myeloproliferative disorders (MPDs). It is also known as agnogenic myeloid metaplasia or meylofibrosis with myeloid metaplasia. Myelofibrosis means fibrosis of the bone marrow. In this form, the marrow becomes fibrous as part of a chronic malignant (cancerous) process in which the proliferation of certain blood cell clones leads to the formation of fibrous tissue.
Idiopathic myelofibrosis is a primary disorder of unknown cause. There is no consistent genetic abnormality. Certain fibrosing growth factors - PDGF and TGFb have been involved and their source is almost certainly the immature platelet precursors. Secondary MF develops as a result of another condition, usually from other MPDs such as Essential Thrombocythaemia (ET) or Polycythaemia Vera (PV). Sometimes secondary MF can occur as a reaction to other disorders such as auto immune/inflammatory conditions or cancers like Hodgkin’s Disease. Persons who were exposed to benzene or high doses of radiation have developed myelofibrosis.
There may be an association between myelofibrosis and autoimmune diseases, such as systemic lupus erythematosus and scleroderma, in which the immune system treats certain molecules of the body as foreign invaders. Myelofibrosis is rare, affecting less than 2 of 100,000 people in the United States. It occurs most commonly among people between the ages of 50 and 70. Symptoms usually appear gradually over a long period of time. About one quarter of all patients with myelofibrosis have no symptoms (asymptomatic). Symptoms of myelofibrosis include low platelet count, anemia, and an enlarged spleen.
In a while stages, general malaise, weight loss, night sweats and low-grade fever. Extramedullary haematopoiesis may cause symptoms, depending on the organ or site of involvement. Splenomegaly may result in left upper quadrant discomfort. Splenic infarcts, perisplenitis, or subcapsular hematoma may cause severe left upper quadrant or left shoulder pain. Treatment is often challenging and is largely supportive. Bone marrow transplantation may be used to treat some patients with myelofibrosis. Androgens, corticosteroids and erythropoietin are useful for the treatment of anaemia. Treatment with imatinib mesylate is occasionally effective.
