blood disorders
Acute Lymphoblastic Leukemia (ALL)
Introduction
Acute lymphoblastic leukemia is a life-threatening disease in which the cells that normally develop into lymphocytes (a type of White Blood Cells ) become cancerous and rapidly replace normal cells in the bone marrow. People may have symptoms, such as fever, weakness, and paleness, because they have too few normal blood cells. Blood tests and a bone marrow evaluation are usually done. Chemotherapy is given and is often effective. (See also Overview of Leukemia ) Acute lymphoblastic leukemia (ALL) occurs in people of all ages but is the most common cancer in children, accounting for 75% of all Overview of Leukemia in children younger than 15 years. ALL most often affects young children between the ages of 2 and 5 years. Among adults, it is somewhat more common in people older than 45. In ALL, very immature leukemia cells accumulate in the bone marrow, destroying and replacing cells that produce normal blood cells, including one or more of the following: Red Blood Cells , which carry oxygen in the bloodstream White Blood Cells , which help defend the body against infection Platelets , small cell-like particles that help in the clotting process The cancerous white blood cells do not function like normal white blood cells so they cannot help the body fight off infections. The leukemia cells also are carried in the bloodstream to the liver, spleen, lymph nodes, brain, and testes, where they may continue to grow and divide. However, ALL cells can accumulate anywhere in the body. They can spread to the layers of tissue covering the brain and spinal cord (leukemic meningitis) and cause anemia, liver failure, kidney failure, and other organ damage. 