Myelofibrosis Overview

Myelofibrosis (MF) is a rare form of bone marrow cancer that is part of a larger classification of related blood cancers known as myeloproliferative neoplasms (MPNs). The disease results in extensive scarring in your bone marrow that ultimately disrupts the normal production of blood cells. 

What is Myelofibrosis?

Myelofibrosis is a bone marrow disorder in which the cells that produce the body’s blood cells function abnormally. It is helpful to understand the etymology of myelofibrosis to understand the disease better.

  • Myelo – a prefix meaning marrow 
  • Fibrosis – the thickening of connective tissue

Myelofibrosis is literally the thickening or scarring of connective tissue within the bone marrow. The scarring of the tissue within the bone marrow combined with the overproduction of abnormal blood cells eventually impacts the production of healthy red blood cells, white blood cells and platelets. If left unchecked, myelofibrosis can lead to serious health conditions like severe anemia or an enlarged spleen and liver.

Anemia is a major problem. The spleen symptoms and anemia is the major reason why to treat the patients.

Dr. Srdan Verstovsek | Read more about MF symptoms and treatment options

What Else is Myelofibrosis Called?

Myelofibrosis goes by many names. Some of the common synonyms for myelofibrosis include:

  • Idiopathic myelofibrosis (IM)
  • Agnogenic myeloid metaplasia (AMM)
  • Chronic idiopathic myelofibrosis (CIMF)
  • Myelofibrosis with myeloid metaplasia (MMM)

Is Myelofibrosis Cancer?

Myelofibrosis is part of a group of diseases known as myeloproliferative neoplasms (MPNs), which are characterized by the overproduction of the three types of blood cells: white, red and platelets. Other MPNs include essential thrombocythemia, polycythemia vera and chronic myeloid leukemia.

Because MPNs, including myelofibrosis, are characterized by uncontrolled cell growth, they are considered a form of blood cancer. 

What are Myeloproliferative Neoplasms? Learn more about the group of diseases known as MPNs.

Is Myelofibrosis Leukemia?

According to the National Cancer Institute, leukemia is a form of cancer that starts in blood-forming tissue, such as the bone marrow, in which amounts of abnormal blood cells are produced and enter the bloodstream. 

As a form of cancer resulting in the bone marrow producing an abundance of abnormal blood cells, myelofibrosis fits the definition of leukemia.

How Many People Have Myelofibrosis?

As we think of MPN patients, people have a sense there’s about 300,000, maybe 400,000 patients with ET and PV in the United States. There’s probably about 20,000 to 30,000 with myelofibrosis. 

Dr. Ruben Mesa | Read More

Primary Myelofibrosis vs. Secondary Myelofibrosis

Myelofibrosis can be either primary or secondary. So what’s the difference between the two?

Primary myelofibrosis (PMF) is MF diagnosed without a preceding MPN or blood disorder. While the cause of PMF is unknown, it is linked with the mutation of specific genes. According to the Leukemia and Lymphoma Society, approximately 50% of people with PMF have a mutation of the JAK2 gene. Other commonly linked gene mutations include the CALR and MPL genes. However, some people with PMF don’t have any identified gene mutations.

Secondary myelofibrosis is MF that occurs as the result of another disease or disorder. Occasionally, other myeloproliferative neoplasms like polycythemia vera or essential thrombocythemia can progress into myelofibrosis in what is known as the “spent phase” of these diseases.

What is Pre-Fibrotic Myelofibrosis?

In 2016 the World Health Organization made a distinct division of myelofibrosis into overt-myelofibrosis (overt-MF) and pre-fibrotic (pre-MF). The division addresses a grey area in which signs and symptoms of myelofibrosis were present in a patient, but they don’t meet the criteria for diagnosis of MF or another MPN. 

Pre-fibrotic myelofibrosis can mimic essential thrombocythemia or polycythemia vera in several ways, including presenting almost no noticeable symptoms but remaining progressive for several years. While pre-MF may seem similar to PV or ET, it has its own unique set of diagnostic criteria, one of which it’s the absence of another myeloid disorder.

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