There are many procedures and tests to see if and where cancer cells are present in the body. The exact combination of testing used to diagnose a child depends on the symptoms that are present and the suspected type of cancer.
For any test that is performed, it is important to understand:
- Why the test is being done
- What the test will feel like and how it will be done
- What risks are associated with the test
- What preparations may need to be done before the test
- Strategies to support your child prior to, during, and after the procedure
Typically, cases of Wilms tumor are not diagnosed until the tumor becomes quite large. Fortunately, most tumors are discovered before they metastasize (spread to other organs in the body).
As with many cancers, the tumor mass can become quite large; the average weight of a newly discovered Wilms tumor is about 500 grams (one pound), which is larger than the normal kidney.
What tests are done to make a diagnosis of Wilms tumor?
In addition to a complete medical history and physical examination, diagnostic tests are performed to evaluate the Wilms tumor and look for signs of spread to other areas of the body.
- Laboratory Tests: Certain blood tests are done to count the number of white blood cells, to look for anemia (low number of red blood cells) and to measure certain chemicals and salts in the blood that give clues about how well the kidneys are working.
- Urinalysis: A urine sample is examined using various testing methods for the presence of blood and other substances.
- Imaging studies: Many technologies are available to get a clear picture of the tumor and surrounding structures, these include:
These tests also enable the treating doctors and surgeons to select the best approach for treatment. These tests show where the tumor si which will often suggest the type of tumor. The diagnosis is usually confirmed by the surgical removal of all or part of the tumor. The diagnosis is then confirmed by the pathologist who will look at the tumor under the microscope.
In some cases, it is not advisable to perform surgery because it might be dangerous for the child. In these cases, treatment with chemotherapy will be started to shrink the tumor and make removal safer at a later time.
Shirley Perry, RN, Oncology Nurse Practitioner, Stollery Children's Hospital
May 2008