MedlinePlus Medical Encyclopedia: Primary myelofibrosis

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Primary myelofibrosis

Contents of this page:
Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Alternative names

Myelofibrosis; Idiopathic myelofibrosis; Myeloid metaplasia; Agnogenic myeloid metaplasia

Definition Return to top

Primary myelofibrosis is a disorder of the bone marrow in which the marrow is replaced by fibrous (scar) tissue.

Causes, incidence, and risk factors Return to top

In primary myelofibrosis, a progressive scarring (fibrosis) of the bone marrow occurs. This causes blood formation to take place in sites other than the bone marrow, such as the liver and spleen, causing enlargement of these organs. The cause is unknown.

The disorder usually develops slowly, in people over 50 years old. It leads to progressive bone marrow failure with severe anemia. Low platelet count leads to easy bleeding, and spleen enlargement continues. The disease gets progressively worse in most cases. Risk factors are unknown.

Symptoms Return to top

Fatigue
Abdominal fullness related to an enlarged spleen
Easy bleeding
Bone pain
Pallor (paleness)
Shortness of breath on exertion
Bruising
Increased susceptibility to infection

Signs and tests Return to top

Physical examination shows an enlarged spleen. Later in the disease, it may also show an enlarged liver.

An examination of the blood shows teardrop-shaped red blood cells.
The white blood cell count is variable.
The platelet count is variable.
Bone marrow biopsy may be performed to rule out other causes of the symptoms.
CBC (complete blood count) shows a low red blood cell count.

Treatment Return to top

There is no specific treatment for primary myelofibrosis. Blood transfusions are given to correct anemia. Recombinant erythropoietin or androgens may stimulate red blood cell production and may be beneficial. A splenectomy (removal of the spleen) may help if the enlarged size of the spleen causes symptoms. Radiation and chemotherapy may also be used. In young people, bone marrow transplants appear to improve the outlook.

Expectations (prognosis) Return to top

The average survival of people with primary myelofibrosis is about 5 years. However, many people survive for decades. In the end stages, myelofibrosis is a wasting, debilitating illness.

Complications Return to top

Liver failure
Acute myelogenous leukemia

Calling your health care provider Return to top

Call for an appointment with your health care provider if symptoms of this disorder develop. Uncontrolled bleeding, shortness of breath, jaundice, and progressive confusion are symptoms that indicate a need for urgent or emergency care.

Prevention Return to top

There is no known prevention.

Update Date: 7/31/2003

Updated by: Corey Cutler, M.D., M.P.H., F.R.C.P.C., Department of Medical Oncology, Dana-Farber Cancer Institute; Instructor of Medicine, Harvard University, Boston, MA. Review provided by VeriMed Healthcare Network.

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