a disease in which the bone marrow is taken over by fibrous tissue and is no longer able to: produce adequate numbers of mature blood cells. Often accompanied by enlargement of the spleen.

A term that means the prominent replacement of the marrow by fibrous tissue. Fibrous tissue is composed of fibroblasts and the fibers they make, such as collagen. The disease idiopathic myelofibrosis or agnogenic myeloid metaplasia is a neoplastic disorder manifested by anemia and elevated white cell and platelet counts. The spleen is enlarged, often dramatically so. The abnormal megakaryocytes in the marrow release factors that stimulate marrow fibroblasts to proliferate and elaborate fibrous tissue(collagen fibers). The proliferation of fibroblasts is a secondary reaction, not a part of the cancer.

Abnormal replacement of blood stem cells in the bone marrow with fibrous tissue. Myelofibrosis occurs as a complication of CML and its treatments, especially interferon.

Also called agnogenic myeloid metaplasia. A chronic disease characterized by fibrous material in the bone marrow, an enlarged spleen and anemia. (Read about " The Spleen" " Anemia")

A disease that causes scar tissue to form in the bone marrow. As a result of the scar tissue, normal blood cell production is blocked. Normal blood cell production then moves to the spleen which then becomes enlarged. Anemia results because blood production in the spleen does not work as well as in the bone marrow.

A disorder in which the bone marrow is replaced by fibrous tissue.

Myelofibrosis, one of the myeloproliferative diseases, is the gradual replacement of the bone marrow by connective tissue.