Primary myelofibrosis

Primary myelofibrosis (PMF) is a rare bone marrow blood cancer.^[1] It is classified by the World Health Organization (WHO) as a type of myeloproliferative neoplasm, a group of cancers in which there is activation and growth of mutated cells in the bone marrow. This is most often associated with a somatic mutation in the JAK2, CALR, or MPL genes. In PMF, the bony aspects of bone marrow are remodeled in a process called osteosclerosis; in addition, fibroblast secrete collagen and reticulin proteins that are collectively referred to as (fibrosis). These two pathological processes compromise the normal function of bone marrow resulting in decreased production of blood cells such as erythrocytes (red cells), granulocytes and megakaryocytes, the latter cells responsible for the production of platelets.

Signs and symptoms include fever, night sweats, bone pain, fatigue, and abdominal pain. Increased infections, bleeding and an enlarged spleen (splenomegaly) are also hallmarks of the disease. Patients with myelofibrosis have an increased risk of acute meyloid leukemia and frank bone marrow failure.

In 2016, prefibrotic primary myelofibrosis was formally classified as a distinct condition that progresses to overt PMF in many patients, the primary diagnostic difference being the grade of fibrosis.^[2]