Leukemia (continued)

To limit the risk of prenatal radiation exposure as a trigger for leukemia (especially ALL), women who are pregnant or who suspect that they might be pregnant should always inform their doctors before undergoing tests or medical procedures that involve radiation (such as X-rays).

Regular checkups can spot early symptoms of leukemia in the relatively rare cases where this cancer is linked to an inherited genetic problem, to prior cancer treatment, or to use of immunosuppressive drugs for organ transplants.

Symptoms

Because infection-fighting white blood cells are defective in children with leukemia, these children may experience increased episodes of fevers and infections.

They may also become anemic because leukemia affects the bone marrow's production of oxygen-carrying red blood cells. This makes them appear pale, and they may become abnormally tired and short of breath while playing.

Children with leukemia may also bruise and bleed very easily, experience frequent nosebleeds, or bleed for an unusually long time after even a minor cut because leukemia destroys the bone marrow's ability to produce clot-forming platelets.

Other symptoms of leukemia may include:

• pain in the bones or joints, sometimes causing a limp
• swollen lymph nodes (sometimes called swollen glands) in the neck, groin, or elsewhere
• an abnormally tired feeling
• poor appetite

In about 12% of children with AML and 6% of children with ALL, spread of leukemia to the brain causes headaches, seizures, balance problems, or abnormal vision. If ALL spreads to the lymph nodes inside the chest, the enlarged gland can crowd the trachea (windpipe) and important blood vessels, leading to breathing problems and interference with blood flow to and from the heart.

Diagnosis

Your child's doctor will perform a physical examination to check for signs of infection, anemia, abnormal bleeding, and swollen lymph nodes. The doctor will also feel your child's abdomen to see if there is an enlarged liver or spleen because they can become enlarged with some cancers in children. In addition to doing a physical examination, the doctor will ask you about any concerns and symptoms you have, your past health, your family's health, any medications you're taking, any allergies you may have, and other issues. This is called the medical history.

After this exam, the doctor will order a CBC (complete blood count) to measure the numbers of white cells, red cells, and platelets in your child's blood. A blood smear will also be examined under a microscope to check for certain specific types of abnormal blood cells that are typically seen in patients with leukemia. Blood chemistries will also be checked.

Then, depending on the results of your child's physical exam and preliminary blood tests, your child may need the following:

• a bone marrow biopsy and aspiration, in which marrow samples are removed from the body (usually from the back of the hip) for testing
• a lymph node biopsy, in which lymph nodes are removed and examined under a microscope to look for abnormal cells
• a lumbar puncture (spinal tap), where a sample of spinal fluid is removed from the lower back and examined for evidence of abnormal cells. This will show whether the leukemia has spread to the central nervous system (brain and spinal cord).

Bone marrow or lymph node samples will be examined and additional testing will be done to determine the specific type of leukemia. In addition to these basic lab tests, cell evaluations are also generally done, including genetic studies to distinguish between specific types of leukemia, as well as certain features of the leukemia cells. Children will receive anesthesia or sedative medications for any painful procedures.