NATIONAL CANCER INSTITUTE
acute lymphoblastic leukemia
(uh-KYOOT LIM-foh-BLAS-tik loo-KEE-mee-uh)
A type of leukemia (blood cancer) that comes on quickly and is fast growing. In acute lymphoblastic leukemia, there are too many lymphoblasts (immature white blood cells) in the blood and bone marrow. Also called acute lymphocytic leukemia and ALL.