Wilms Tumor

Wilms tumor can occur at any age and is equally common in boys and girls. It is usually diagnosed in children around 3 years of age. It is more common in African-Americans than in Caucasians and is less common in Asian children.

There are often no symptoms for Wilms tumor until the cancer is advanced and the tumor is large. You or your child may feel or see a firm lump, especially on one side of the body. Other symptoms of Wilms tumor include:

• Swelling of the abdomen
• Abdominal pain
• Fever
• Hematuria (blood in the urine)
• High blood pressure

It is uncommon for Wilms tumor to run in families. There are no known environmental risk factors, although more research is needed. For most children, there is no known cause, although children with certain syndromes are more likely to develop Wilms tumor. These syndromes include: 

• WAGR syndrome. This is a disorder that affects many body systems and is named for its main features—Wilms tumor, aniridia (lack of irises in the eyes) and abnormal development of genitalia, especially in boys. 
• Denys-Drash syndrome. This condition is characterized by kidney disease that begins within the first few months of life. 
• Beckwith-Wiedemann syndrome. Children born with this condition are considerably larger than normal (macrosomia) as infants and tend to be taller than their peers during childhood. In some children, specific parts of the body or one side of the body may grow abnormally large, leading to an asymmetric or uneven appearance. This is called hemihypertrophy.

The outlook for survival depends on the extent of the condition and how aggressive the cancer is. For most patients, long-term survival is excellent. Eighty-five to 90 percent of Wilms tumor patients who have less aggressive cancers are cured with treatment. Patients with more aggressive tumors require more intensive treatments. All patients require long-term medical follow-up care for chronic medical problems such as high blood pressure.

Diagnosis of Wilms Tumor

If your child has symptoms of Wilms tumor, a pediatric oncologist at Riley at IU Health can schedule the following studies and procedures to make a diagnosis:

• Ultrasound. Ultrasound uses high-frequency sound waves to create pictures of the inside of the body. The doctor may use this imaging tool to detect Wilms tumor in the kidneys.
• Computed tomography (CT). This fast, painless imaging procedure creates multiple detailed or three-dimensional images of the kidneys to detect a tumor.
• Biopsy. A sample of tumor tissue is removed and examined under a microscope.