SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.
PMF is a disorder of the bone marrow in which the marrow is replaced by fibrous tissue. This is a clonal myeloproliferative disease which is characterized by a proliferation of mainly megakaryocytic and granulocytic elements in bone marrow. It is associated with reactive deposition of bone marrow connective tissue and with extra-medullary hematopoiesis (EMH).
Primary myelofibrosis begins with a hypercellular marrow with absence of overt fibrosis and often with early increase in reticulin fibers. This is call the "prefibrotic" stage of primary myelofibrosis.
Primary myelofibrosis is a rare bone marrow disorder characterized by abnormalities in blood cell production and progressive scarring of the bone marrow. Blood forms in sites other than bone marrow such as liver and spleen. The blood and bone marrow are always involved. Blood transfusions are given to correct anemia and should not be listed as treatment. Splenectomy may be done if the patient is symptomatic . About 50% exhibit JAK2 gene mutation, but the test is not specific enough to provide a definitive diagnosis. This disease is diagnosed clinically (a diagnosis of exclusion). The physician correlates information from JAK2 (if available), the equivocal results of the bone marrow and blood work with the clinical symptoms to arrive at a diagnosis of primary myelofibrosis.
In the early stages of disease, CD34 may be slightly increased in the bone marrow but not in the peripheral blood. In the later stages CD34 will appear in large numbers. This is peculiar to Primary myelofibrosis and does not occur in Polycythemia vera or Essential thrombocythemia.