A thorough examination must be conducted to determine the presence of childhood cancer. First, the physician will obtain a complete medical history from the child and the parents including any family history of cancer, symptoms, risk factors and other related medical information. Following the history, the physician will conduct a complete physical examination with emphasis on the affected areas.

In addition to the medical history and physical examination, diagnostic procedures for cancer can include one or more of the following tests:

• Blood tests. Tests that may be used in the diagnosis of childhood cancers include:
  
• • Complete blood count (CBC). Measures the number, size and maturity of blood cells in a specific volume of blood. An increased number of white blood cells can indicate an infection and abnormal cells may indicate cancer.
    
    
  • Liver function tests. Evaluate the liver’s ability to make protein, remove toxins and maintain normal blood sugar. Liver blood tests can measure certain proteins and enzymes that indicate liver injury or damage.
    
    
  • Kidney function tests. Blood urea nitrogen test (BUN) and creatinine test are two tests used to evaluate kidney function. These tests measure the amount of waste products present in the blood. Elevated levels can indicate impaired kidney function.
    
    
  • Tumor marker tests. Identify substances in the blood that are associated with certain types of cancers.
    
    
  • Genetic tests.  Evaluate DNA for abnormalities that are linked to certain diseases or conditions. Examining the blood for chromosome changes or mutations may help confirm the diagnosis of leukemia.
    
    
• Biopsy.  A removal of a sample of tissue, usually from a tumor.  The tissue is examined under a microscope by a pathologist for evidence of cancer cells. A tissue biopsy is necessary for the diagnosis of cancer.
  
  
• Bone marrow biopsy. A small amount of bone marrow tissue is removed, usually from the hip bone. If only bone marrow fluid is taken, it is a bone marrow aspiration. The tissue and/or fluid is examined for normal and abnormal cells.
  
  
• Spinal tap (lumbar puncture). A small amount of cerebral spinal fluid (CSF) is removed from the spinal canal through a special needle that is placed into the lower back. CSF is evaluated for pressure, infection, or abnormal cells. It is the fluid that surrounds a child’s brain and spinal cord.
  
  
• X-rays. Test that uses radiation energy beams to produce images on film. X-rays may be taken of any part of the body to detect a growth or abnormality of an organ.
  
  
• CAT scan.  Imaging procedure that uses computer technology to produce cross sectional images of the body. The test may be done with or without dye (contrast material). CAT scans show detailed images of the selected part of the body and can help determine the size, shape and position of a tumor and enlarged lymph nodes.
  
  
• Magnetic resonance imaging (MRI). A procedure that uses powerful magnets, radio waves and a computer to create detailed images of organs and structures in the body.
  
  
• PET scan. A radioactively controlled glucose (sugar) substance is injected into the vein and the body is viewed by a scanner. Cancer cells absorb the substance and malignant areas appear as hot spots on the images.
  
  
• Ultrasound. Imaging technique that uses high frequency sound waves and a computer to create images of blood vessels, tissues and organs. This test is used to evaluate the function of internal organs and blood flow and can detect tumors in the abdomen, liver and kidneys.
  
  
• Lymphangiogram (LAG). A type of radiologic study that detects abnormalities in the lymph system. Dye is injected into the lymph system for analysis. This test is rarely used today because newer studies are more easily performed and more reliable.

The type of tests that are used to diagnose cancer in children vary depending on the suspected cancer. For example, leukemia does not produce tumors, so a tissue biopsy would not be performed to diagnose the cancer.