Definition of Lymphoblastic leukemia, acute (ALL)

Lymphoblastic leukemia, acute (ALL): A form of leukemia that has a sudden onset and is characterized by the presence in the blood and bone marrow of large numbers of unusually immature white blood cells destined to become lymphocytes. These cells, called lymphoblasts, are rarely seen in the blood under normal circumstances. Treatment may include chemotherapy, radiation, biological therapy and bone-marrow transplantation. There is a high cure rate today, especially among children. Also called acute lymphocytic leukemia and abbreviated ALL.(ALL is spoken not as the word "all", but as the three letters: A.L.L.)