In 2010, the World Health Organization (WHO) classified Myelofibrosis as a neoplasm. It was during this time period that people diagnosed with myelofibrosis were considered to have cancer. Myelofibrosis is one of three most common myeloproliferative neoplasms (MPN), blood cancers that overproduce blood cells in the bone marrow and are caused by genetic mutations in the blood stem cells.
In people who have no symptoms, MF may be suspected when a routine medical checkup reveals an enlarged spleen and abnormal blood test results. The results of a blood test (a complete blood count, or CBC) that suggest a diagnosis of MF often include:
- A decrease in the number of red blood cells (anemia) below the normal range
- An increase or decrease in the number of white blood cells
- An increase in platelets above the normal range (occurs in about one-third of MF patients)
- A mild to moderate decrease in platelets below the normal range (occurs in about one-third of MF patients)
Myelofibrosis occurs in about 1.5 out of every 100,000 people in the United States annually. The disease affects both men and women and is usually diagnosed in people over the age of 50; however, myelofibrosis can occur at any age. Myelofibrosis is a type of chronic leukemia (cancer of the blood) and can occur on its own (primary myelofibrosis) or as a result of another bone marrow disorder (secondary myelofibrosis). In primary myelofibrosis, a genetic mutation in a single blood-forming stem cell disrupts the body’s production of normal blood cells, including the red blood cells, white blood cells, and platelets. As in most cancer processes, the abnormal cells begin to take over the normal cells, which leads to a disruption in the function that those cells serve. It also leads to extensive scarring in the bone marrow, known as fibrosis.
Learn more about Myelofibrosis, download the fact sheet