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
- 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.
It's not clear what causes Wilms' tumor.
Doctors know that cancer begins when cells develop errors in their DNA. The errors allow the cells to grow and divide uncontrollably and to go on living when other cells would die. The accumulating cells form a tumor. In Wilms' tumor, this process occurs in the kidney cells.
In a small number of cases, the errors in DNA that lead to Wilms' tumor are passed from parents to children. In most cases, there is no known connection between parents and children that may lead to cancer.
Factors that may increase the risk of Wilms' tumor include:
- Being black. Black children have a slightly higher risk of developing Wilms' tumor than do children of other races. Children of Asian descent appear to have a lower risk than do children of other races.
- Having a family history of Wilms' tumor. If someone in your child's family has had Wilms' tumor, then your child has an increased risk of developing the disease.
Wilms' tumor occurs more frequently in children with certain abnormalities present at birth, including:
- Aniridia. In this condition the iris — the colored portion of the eye — forms only partially or not at all.
- Hemihypertrophy. A condition that occurs when one side of the body is noticeably larger than the other side.
- Undescended testicles. One or both testicles fail to descend into the scrotum (cryptorchidism).
- Hypospadias. The urinary (urethral) opening is not at the tip of the penis, but is on the underside.
Wilms' tumor can occur as part of rare syndromes, including:
- WAGR syndrome. This syndrome includes Wilms' tumor, aniridia, abnormalities of the genitals and urinary system, and mental retardation.
- Denys-Drash syndrome. This syndrome includes Wilms' tumor, kidney disease and male pseudohermaphroditism, in which a boy is born with testicles but may exhibit female characteristics.
- Beckwith-Wiedemann syndrome. Signs of this syndrome include abdominal organs that protrude into the base of the umbilical cord, a large tongue (macroglossia) and enlarged internal organs.
Wilms' tumor can't be prevented by anything you or your child can do.
If your child has signs and symptoms that increase the risk of Wilms' tumor, your child's doctor may recommend periodic kidney ultrasounds to look for kidney abnormalities. While this screening can't prevent Wilms' tumor, it may help detect the disease at an early stage, when treatment is most likely to be successful.