Wilms Tumor

A Wilms tumor is a type of cancer in which a tumor grows on a kidney. It happens most often in children younger than 5.

• Doctors don’t know what causes Wilms tumors, but children who have certain health problems at birth are more likely to get them

• Children with a Wilms tumor have a lump in their belly and may throw up and have belly pain, fever, poor appetite, and upset stomach

• A Wilms tumor usually affects one kidney, but it can affect both

• Treatment includes surgery, chemotherapy, and sometimes radiation therapy

Most of the time, doctors don’t know what causes Wilms tumors. Sometimes it's caused by a problem with the child's genes.

The first symptom of a Wilms tumor is usually:

• A painless lump in a child's belly

Other symptoms include:

• A swollen belly (sometimes parents notice that a young child suddenly needs a larger-sized diaper)

• Belly pain, fever, poor appetite, upset stomach, and throwing up

• Blood in the urine

• High blood pressure

If the cancer spreads to the lungs, it may cause coughing and shortness of breath.

Doctors suspect a Wilms tumor if they feel a lump in a child's belly. To know for sure, they'll do:

• Ultrasound, CT (computed tomography) scan, or MRI (magnetic resonance imaging)

• Surgery to remove the lump—doctors will look at it under a microscope to see if it's a Wilms tumor

Doctors also use CT scan or MRI to see if any cancer has spread to the lymph nodes, liver, or lungs.

To treat a Wilms tumor, doctors will:

• Do surgery to remove the kidney that has the tumor

• During surgery, check the other kidney for cancer

• After surgery, treat the child with chemotherapy

• If the cancer has spread, do radiation therapy

In rare cases where a tumor is very large or is in both kidneys, doctors will use chemotherapy to shrink the tumor or tumors before doing surgery to remove them.