Wilms tumor (WT) is a type of kidney cancer that occurs in children.
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. More than 90% of cases are diagnosed before 10 years of age. In rare cases, it is seen in children older than 15 years of age, and in adults.
Symptoms may include any of the following:
The health care provider 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.
Other tests needed to determine if the tumor has spread may include:
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.
Children whose tumor has not spread have a 90% cure rate with appropriate treatment. Prognosis is also better in children younger than 2 years of age.
The tumor may become quite large, but usually remains self-enclosed. Spread of the tumor to the lungs, lymph nodes, 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.
Other possible complications of the long-term treatment of WT may include:
Call your child's provider if:
For children with a known high risk for WT, screening using ultrasound of the kidneys or prenatal genetic analysis may be suggested.
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.