Wilms Tumor: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Wilms Tumor?
A pediatric oncologist, a doctor who treats children with cancer, usually leads care for Wilms tumor. A pediatric surgeon, a surgeon who operates on children, removes the tumor. Your child's pediatrician can check early signs first. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is Wilms tumor?
Wilms tumor is a rare type of kidney cancer. It causes a tumor on one or both kidneys. It usually affects children, but it can happen in adults.
Wilms tumors have often grown large by the time they are found.
Symptoms
Symptoms of Wilms tumor include:
- A lump or swelling in the belly.
- Blood in the urine.
- A fever for no known reason.
Doctors also check for high blood pressure, which is another possible sign of a kidney tumor.
Causes and who gets it
Having certain genetic conditions or birth defects can raise the risk of Wilms tumor. Genetic conditions are health problems that come from changes in a child's genes.
Children who are at risk should be screened for Wilms tumor every three months until they turn eight. Doctors may also ask if there is a family history of cancer or birth defects.
How doctors diagnose it
Doctors start with a medical history and a physical exam. They focus on the belly and on blood pressure. Blood and urine samples might also be tested.
Imaging tests make pictures of the inside of the body. An ultrasound is often the first imaging test, and it does not use radiation.
A CT scan is one of the most useful tests to look for a tumor inside the kidney. An MRI gives very detailed pictures without using x-rays. A chest x-ray can look for spread to the lungs.
Younger children may be given medicine to stay calm or asleep during a scan.
Imaging does not make the final diagnosis. The diagnosis is made when a small piece of the tumor is checked under a microscope.
Most often, this is done on the tumor after it is removed during surgery. Sometimes a sample is taken first in a procedure called a biopsy.
Treatment
Surgery is the main treatment for nearly all children with Wilms tumor. It should be done by a surgeon who specializes in operating on children and has experience with these cancers.
The main goal of surgery is to remove the whole tumor in one piece, if possible.
A radical nephrectomy removes the whole kidney and some nearby parts. This is the most common surgery for a tumor in only one kidney. Most children do very well afterward with only one kidney.
A partial nephrectomy removes only part of the kidney. It may be used when both kidneys have tumors, to try to save some normal kidney tissue.
Other treatments include chemotherapy, which is strong medicine that kills cancer cells, and radiation, which uses high-energy rays. Biologic therapy boosts the body's own ability to fight cancer.
Almost all children have some pain for a while after the operation. Serious problems during surgery are rare.
When to see a doctor
Take your child to a doctor if you notice a lump or swelling in the belly, blood in the urine, or a fever for no known reason. Tests are needed to find out the cause of a lump in the belly.
Call 911 or go to the emergency room if your child has trouble breathing, a seizure, unconsciousness, or a big change in alertness.
If your child has a genetic condition or birth defect that raises the risk, ask the doctor about screening every three months.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either can look at a lump in the belly or blood in the urine and send your child quickly to a children's cancer team. They can also help with follow-up visits and keep your child's doctors in touch with one another.
Common questions
What is the main treatment for Wilms tumor?
Surgery is the main treatment for nearly all children with Wilms tumor. Chemotherapy and radiation are used as other treatments.
Is Wilms tumor only found in children?
No, Wilms tumor usually affects children, but it can happen in adults.
Can Wilms tumor affect both kidneys?
Yes, Wilms tumor can cause a tumor on one or both kidneys. When both kidneys have tumors, doctors may remove only part of the kidney to save some normal tissue.
How do doctors confirm Wilms tumor?
Doctors confirm Wilms tumor by checking a small piece of the tumor under a microscope. Imaging tests alone do not make the final diagnosis.
Can a child live with one kidney?
Yes, most children do very well afterward with only one kidney.
Sources
- MedlinePlus - Wilms Tumor
- American Cancer Society - Diagnosing Wilms Tumors
- American Cancer Society - Surgery for Wilms Tumors
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
