Myelofibrosis is a serious bone marrow disorder resulting in extensive scarring of the bone marrow. It is a rare form of chronic leukemia affecting up to 18,000 people in the United States. 

Scarring of the bone marrow causes disruption to the normal production of blood cells and the resultant damage to this tissue can lead to a number of other complications, such as anemia, weakness, fatigue and an enlarged spleen. Symptoms of myelofibrosis include easy bruising and bleeding, night sweats, fever, and bone pain. 

Other complications associated with myelofibrosis include the development of tumors elsewhere in the body, bleeding complications, painful bones, and joints, and increased pressure in blood passing through the liver, increasing the risk of ruptures or bleeds. Risk factors for myelofibrosis include being over 50 years of age, other blood cell disorders, such as thrombocythemia, exposure to certain industrial chemicals, and exposure to radiation. 

Treatment options for myelofibrosis include chemotherapy, radiation therapy, blood transfusions and medication. Protein kinase inhibitors may be prescribed as to treat myelofibrosis.