Wilms tumor, a nephroblastoma, is a form of cancer that originates in the kidneys named after Max Wilms, a German doctor. Although a rare form of cancer, Wilms tumors are the most common type of kidney cancer among children.
In the United States, there are approximately 500 new cases of Wilms tumors diagnosed each year with the average age at the time of diagnosis being around 3 and 4.
Although it is unclear why, but African-American children seem to be affected slightly more than children of other races and girls tend to be afflicted with Wilms tumors more than boys.
Wilms tumors can be hard to find early because they can often grow quite large without causing any symptoms. Children may look healthy and play normally.
Swelling or a hard mass in the abdomen (belly): This is often the first sign of a Wilms tumor. Parents may notice this while bathing or dressing the child. It feels firm and is often large enough to be felt on both sides of the belly. It’s usually not painful, but it might cause belly pain in some children.
Other possible symptoms: Some children with Wilms tumor may also have:
For many,Wilms tumors are a result of gene changes that occur early in the child’s life, maybe even before birth. The genes believed to be involved are the tumor suppressing gene WTX found on the X chromosome and CTNNB1. However, it is still unclear what causes these genes to become altered resulting in Wilms tumors.
1 in 10 children diagnosed with a Wilms tumor also has a birth defect. These birth defects linked to Wilms tumors occur in syndromes. These syndromes include, but are not limited to: