Adult acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many lymphocytes, a type of white blood cell. Some 5,930 adults and children in the United States will be diagnosed with ALL and 1,500 will die of the disease in 2019, the National Cancer Institute reported. Previous chemotherapy and exposure to radiation may increase the risk of developing ALL.
Normally, the bone marrow makes blood stem cells (immature cells) that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. A lymphoid stem cell becomes a lymphoblast cell and then one of three types of white blood cells called lymphocytes
In ALL, too many stem cells become lymphoblasts, B lymphocytes, or T lymphocytes that are not able to fight infection very well. Also, as the number of leukemia cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may cause infection, anemia, and easy bleeding.
Source: National Cancer Institute