Wilms tumor

  • Definition
    • Wilms tumor (WT) is a type of kidney cancer that occurs in children.

  • Alternative Names
    • Nephroblastoma; Kidney tumor - Wilms

  • Causes
    • WT 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 WT. 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. In rare cases, it is seen in children older than 15 years of age, and in adults.

  • Symptoms
    • Symptoms may include any of the following:

  • Exams and Tests
  • Treatment
    • If your child is diagnosed with WT, 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 the provider determine how far the cancer has spread and to plan for the best treatment. Surgery to remove the tumor is planned as soon as possible. Surrounding tissues and organs may also need to be removed if the tumor has spread.

      Radiation therapy and chemotherapy will often be started after surgery, depending on the stage of the tumor.

      Chemotherapy given before the surgery is also effective in preventing complications.

  • Outlook (Prognosis)
    • Children whose tumor has not spread have a 90% cure rate with appropriate treatment.

  • Possible Complications
    • 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 WT from both kidneys may affect kidney function.

  • When to Contact a Medical Professional
    • Call your child's provider if:

      • You discover a lump in your child's abdomen, blood in the urine, or other symptoms of WT.
      • Your child is being treated for this condition and symptoms get worse or new symptoms develop, mainly cough, chest pain, weight loss, or persistent fevers.
  • Prevention
    • For children with a known high risk for WT, screening using ultrasound of the kidneys may be suggested.

  • References
    • Babaian KN, Delacroix SE, Wood CG, Jonasch E. Kidney cancer. In: Skorecki K, Chertow GM, Marsden PA, Taal MW, Yu ASL, eds. Brenner and Rector's The Kidney. 10th ed. Philadelphia, PA: Elsevier; 2016:chap 41.

      National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology (NCCN guidelines): kidney cancer. Updated May 26, 2016. Version 3.2016. Accessed July 11, 2016.

      National Cancer Institute. PDQ Wilms tumor and other childhood kidney tumors treatment. Updated July 7, 2016. Accessed July 11, 2016.