Wilms tumor is a type of kidney cancer that occurs in children.
Nephroblastoma; Kidney tumor
Wilms tumor is the most common form of childhood kidney cancer. The exact cause of this tumor in most children is unknown.
A missing iris of the eye (aniridia) is a birth defect that is sometimes associated with Wilms tumor. Other birth defects linked to this type of kidney cancer include certain urinary tract problems and swelling of one side of the body, a condition called hemihypertrophy.
It is more common among some siblings and twins, which suggests a possible genetic cause.
The disease occurs most often in children about 3 years old. It rarely develops after age 8.
Symptoms may include any of the following:
- Abdominal pain
- Abnormal urine color
- General discomfort or uneasiness (malaise)
- High blood pressure
- Increased growth on only one side of the body
- Loss of appetite
- Swelling in the abdomen (abdominal hernia or mass)
Exams and Tests
The doctor or nurse will perform a physical exam and ask questions about your child’s symptoms and medical history. You will be asked if you have a family history of cancer.
A physical examination may show an abdominal mass. High blood pressure may also be present.
- Abdominal ultrasound
- Abdominal x-ray
- Chest x-ray
- Complete blood count (may show anemia)
- Creatinine clearance
- CT scan of the abdomen
- Intravenous pyelogram
Other tests may be required to determine if the tumor has spread.
If your child is diagnosed with this condition, do not prod or push on the child's belly area. Use care during bathing and handling to avoid injury to the tumor site.
The first step in treatment is to stage the tumor. Staging helps doctors determine how far the cancer has spread and to plan for the best treatment. Surgery to remove the tumor is scheduled as soon as possible. Surrounding tissues and organs may also need to be removed if the tumor has spread.
Children whose tumor has not spread have a 90% cure rate with appropriate treatment.
The tumor may become quite large, but usually remains self-enclosed. Spread of the tumor to the lungs, liver, bone, or brain is the most worrisome complication.
High blood pressure and kidney damage may occur as the result of the tumor or its treatment.
Removal of Wilms tumor from both kidneys may affect kidney function.
When to Contact a Medical Professional
Call your health care provider if you discover a lump in your child's abdomen, blood in the urine, or other symptoms of Wilms tumor.
Call your health care provider if your child is being treated for this condition and symptoms get worse or new symptoms develop, particularly cough, chest pain, weight loss, or persistent fevers.
For children with a known high risk of Wilms tumor, screening using ultrasound of the kidneys may be recommended.
Anderson PM, Dhamne CA, Huff V. Neoplasms of the kidney. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 493.
National Cancer Institute: PDQ Wilms Tumor and Other Childhood Kidney Tumors Treatment. Bethesda, MD: National Cancer Institute. Date last modified: 05/22/2014. Available at: http://cancer.gov/cancertopics/pdq/treatment/wilms/Patient. Accessed May 29, 2014.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines): Kidney cancer. Version 3.2014. Available at: http://www.nccn.org/professionals/physician_gls/pdf/kidney.pdf. Accessed May 29, 2014.
Reviewed By: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.