The Facts

• Myelofibrosis occurs when fibrous tissue displaces areas of blood cell production in the bone marrow, reports the Merck Manuals Online Medical Library (MMOML). It may occur as a singular condition (idiopathic myelofibrosis), or as a consequence of other forms of blood disorders.
  
  

Incidence

• The MMOML notes that myelofibrosis affects less than two in every 100,000 inhabitants of the U.S. It most typically develops in individuals over age 50, reports the Mayo Clinic.
  
  

Associated Disorders

• In addition to blood disorders, other conditions associated with myelofibrosis include lupus, pulmonary hypertension, scleroderma, tuberculosis and cancer that has spread (metastasized) to bone, according to the MMOML.
  
  

Progression

• The Mayo Clinic notes that in some individuals myelofibrosis worsens over time and may develop into a dangerous case of leukemia. However, other individuals with the disorder do not experience any symptoms for years after diagnosis.
  
  

Considerations

• The MMOML notes that some individuals with myelofibrosis survive more than ten years past diagnosis, while others may experience a rapid decline.