Leukemia

progressive proliferation of abnormal leukocytes found in hemopoietic tissues, other organs, and usually in the blood in increased numbers

Description
Leukemia is classified by the dominant cell type, and by duration from onset to death. This occurs in acute leukemia within a few months in most cases, and is associated with acute symptoms including severe anemia, hemorrhages, and slight enlargement of lymph nodes or the spleen. The duration of chronic leukemia exceeds one year, with a gradual onset of symptoms of anemia or marked enlargement of spleen, liver, or lymph nodes.