Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a fast-growing cancer of the white blood cells. Lymphocytes are a type of white blood cell that the body uses to fight infections. In ALL, the bone marrow makes lots of unformed cells called blasts that normally would develop into lymphocytes. However, the blasts are abnormal. They do not develop and cannot fight infections. The number of abnormal cells (or leukemia cells) grows quickly. They crowd out the normal red blood cells, white blood cells and platelets the body needs.