Wilms tumor

[Jason Yan]

Wilms tumor is a specific kind of kidney cancer that occurs mainly in young children.

The cause of Wilms tumor is not known, but some children may have a genetic abnormality that increases their risk of developing this tumor.
Children usually have a lump in the abdomen, and they may also have abdominal pain, fever, poor appetite, nausea, and vomiting.
An imaging test is done to determine the nature and size of the lump.
Treatment involves surgery and chemotherapy and sometimes radiation therapy.

(See also Overview of Childhood Cancer.)
Wilms tumor usually develops in children younger than 5 years old, although it occasionally occurs in older children and rarely in adults. Very rarely, it develops before birth and appears in newborns. In about 5% of cases, Wilms tumor occurs simultaneously in both kidneys.
The cause of Wilms tumor is not known, although a lack of certain genes or another genetic abnormality may be involved in some cases. Wilms tumor is more likely to develop in children with certain birth defects, for example, when both irises are missing or when one side of the body grows too much. Problems with the kidneys, genitals, and urinary tract are common also. These defects, as well as intellectual disability, may be caused by a genetic abnormality. However, most children with Wilms tumor have no such recognizable abnormalities.