Wilms Tumor

If you’ve found a lump near your baby’s diaper line, or you’ve had to move to bigger diapers because of the lump, your healthcare provider may decide to test for Wilms tumor. The tumors sometimes get quite big, even bigger than the kidney itself.

If your child has one of the syndromes or genetic issues associated with Wilms, you and your provider may decide to do regular testing.

Tests to diagnose Wilms tumor include:

• A physical exam that includes pressing down carefully on your child’s abdomen.
• Imaging tests like abdominal ultrasound, CT scan – usually with contrast. Your provider might order an X-ray or CT scan of your child’s chest to find out if cancer has spread (metastasized) to their lungs. Imaging tests can show if your child has a tumor. Your provider can also use the tests to tell the difference between Wilms tumor and other types of kidney cancer.
• Laboratory tests of blood and urine, including liver function and blood clotting tests.
• A biopsy, which means that tissue from the tumor is removed and sent to the laboratory for testing.

What should I know about staging and Wilms tumor?

There are two different ways to stage Wilms tumor. Staging is the name for the way that healthcare providers determine if and how far the cancer has spread beyond its original location. The higher the number, the farther the cancer has spread.

Throughout Europe, healthcare providers use the International Society of Paediatric Oncology (SIOP) staging system. In the U.S. and Canada, healthcare providers use the Children’s Oncology Group (COG) staging system.

One difference between the two systems is that the COG system uses surgery to stage the tumor before chemotherapy. The SIOP system uses surgery after chemotherapy to do the staging.

Under the COG system, staging is as follows:

• A Stage I tumor is only in your child’s kidney and is removed completely during surgery.
• A Stage II tumor has grown past your child’s kidney, but is also removed completely.
• A Stage III tumor isn’t able to be removed completely and some tissue remains in your child’s abdominal area.
• A Stage IV tumor has grown beyond your child’s abdomen and pelvis to places like their lungs, liver, bone or brain.
• A Stage V tumor is bilateral, or present in both kidneys. Your provider will do staging on each kidney separately.