Wilms' tumor

Wilms' tumor is a rare kidney cancer that primarily affects children. Also known as nephroblastoma, Wilms' tumor is the most common cancer of the kidneys in children. Wilms' tumor most often affects children ages 3 to 4 and becomes much less common after age 5.

Wilms' tumor most often occurs in just one kidney, though it can sometimes be found in both kidneys at the same time.

Improvements in the diagnosis and treatment of Wilms' tumor have improved the prognosis for children with this disease. The outlook for most children with Wilms' tumor is very good.

Symptoms Causes Risk factors Prevention

Wilms' tumor doesn't always cause signs and symptoms. Children with Wilms' tumor may appear healthy, or they may experience:

  • Abdominal swelling
  • An abdominal mass you can feel
  • Abdominal pain
  • Fever
  • Blood in the urine

When to see a doctor

Make an appointment with your child's doctor if you notice any signs or symptoms that worry you. The signs and symptoms associated with Wilms' tumor aren't specific to the condition and are much more likely to be caused by something else.

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use