Acute lymphoblastic leukemia (medical condition)

Cancer of the white blood cells. Precursors to white blood cells are called blasts and are made by the bone marrow but in ALL the blasts are abnormal and do not develop into lymphocytes. Instead, the abnormal blasts or leukemic cells multiply rapidly and reduce the level of other types of blood cells such as red blood cells and platelets. See also Acute lymphoblastic leukemia