A disorder in which the bone marrow is replaced by fibrous tissue.
A progressive disease in which the bone marrow is replaced by fibrous tissue and is unable to produce red blood cells; the cause is unknown.
A chronic myeloproliferative disorder characterized by bone marrow fibrosis, proliferation of atypical megakaryocytes and granulocytes in the bone marrow, anemia, splenomegaly, and extramedullary hematopoiesis. The cause is unknown. The median survival time is 3-5 years from diagnosis. (WHO, 2001)