Definition of Acute lymphocytic leukemia (ALL):

Acute lymphocytic leukemia (ALL) is a fast-growing cancer of a type of white blood cells called lymphocytes. These cells are found in the bone marrow and other parts of the body.

See also: Leukemia

Causes, incidence, and risk factors:

Acute lymphocytic leukemia (ALL) occurs when the the body produces a large number of immature white blood cells, called lymphocytes. The cancer cells quickly grow and replace normal cells in the bone marrow. Bone marrow is the soft tissue in the center of bones that helps form blood cells. ALL prevents healthy blood cells from being made. Life-threatening symptoms can occur.

This type of leukemia usually affects children ages 3 - 7. It is the most common childhood acute leukemia. However, the cancer may also occur in adults.

Most of the time, there is no obvious cause. However, the following may play a role in the development of leukemia in general:

• Certain chromosome problems
• Exposure to radiation, including x-rays before birth
• Past treatment with chemotherapy drugs
• Receiving a bone marrow transplant
• Toxins such as benzene

The following increases your risk for this ALL:

• Down syndrome or other genetic disorders
• A brother or sister with leukemia