Tests and diagnosis

By Mayo Clinic Staff

To diagnose Wilms' tumor, your child's doctor may recommend:

  • A physical examination. The doctor will look for possible signs of Wilms' tumor.
  • Blood and urine tests. Blood tests can't detect Wilms' tumor, but they can provide your child's doctor with an overall assessment of your child's health.
  • Imaging tests. Imaging tests that create images of your child's kidneys can help your doctor determine whether your child has a kidney tumor. Imaging tests may include ultrasound, computerized tomography (CT) and magnetic resonance imaging (MRI).
  • Surgery. If your child has a kidney tumor, your doctor may recommend removing the tumor or the entire kidney to determine if the tumor is cancerous. The removed tissue is analyzed in a laboratory to determine whether cancer is present and what types of cells are involved. This surgery may also serve as treatment for Wilms' tumor.


Once your child's doctor has diagnosed Wilms' tumor, he or she works to determine the extent (stage) of the cancer. Your child's doctor may recommend a chest X-ray, chest CT scan and bone scan to determine whether the cancer has spread beyond the kidneys.

The doctor assigns your child's cancer a stage, which helps determine the treatment options. The stages of Wilms' tumor are:

  • Stage I. The cancer is found only in one kidney and generally can be completely removed with surgery.
  • Stage II. The cancer has spread to the tissues and structures near the affected kidney, such as fat or blood vessels, but it can still be completely removed by surgery.
  • Stage III. The cancer has spread beyond the kidney area to nearby lymph nodes or other structures within the abdomen, and it may not be completely removed by surgery.
  • Stage IV. The cancer has spread to distant structures, such as the lungs, liver, bones or brain.
  • Stage V. Cancer cells are found in both kidneys.
Nov. 06, 2014