Types

• Acute lymphocytic leukemia (ALL), is the most common form of childhood leukemia. Acute myeloid leukemia (AML), is less common. Acute forms of childhood leukemia's tend to develop rapidly. Chronic myelogenous leukemia (CML) and chronic lymphocytic leukemia (CLL) aren't really seen that much in children. They grow slower than acute leukemias. Juvenile myelomonocytic leukemia (JMML) is rare. Its growth rate falls between acute and chronic leukemias.
  
  

Causes

• Bone marrow creates stem cells, which develop into mature blood cells. When a child has leukemia, those stem cells create an overabundance of white-blood cells, and they crowd out the space for healthier cells. According to the American Cancer Association, researchers still don't know why this happens. Though risk factors such as Down syndrome, radiation exposure and organ transplantation may contribute to its development. A child whose sibling also had leukemia may be at a higher risk.
  
  

Symptoms

• If a child has leukemia, she may frequently feel tired because of the lack of red-blood cells. Since she don't have normal white-blood cells, she may not be able to fight off fevers or infections easily. And because the abnormal white-blood cells are crowding out the platelets, she may bruise or bleed easily. Other symptoms include pain in the bones or joints, a swollen abdomen, weight loss or trouble breathing. If you notice a combination of these symptoms in your child, call your doctor immediately.
  
  

Diagnosis

• If a doctor suspects leukemia, he'll do a complete examination, including a blood count. The blood count determines if the child is lacking in red blood cells and platelets and whether there are too many white-blood cells. Next, a bone-marrow biopsy is done. During this procedure, a needle is inserted into a bone, and a sample of the marrow is removed. A lab examines the sample to see what types of cells are living in the marrow. A computerized tomography (CT) scan or an X-ray tells the doctor if the leukemia has spread. And if he wants to see if it has spread to the spinal fluid, he'll do a lumbar-puncture test.
  
  

Treatment

• Treatment will begin once the child has been diagnosed and the doctor knows what stage of leukemia the child is in. Treatment may take 2 1/2 to 3 years and may include chemotherapy and radiation. In targeted-drug therapy, certain medications are given to the child to fight parts of the cancer cells. It can be combined with chemotherapy. Bone-marrow transplants are done when there's a risk of relapse or if a relapse has just occurred.