Wilms' tumor is a rare type of kidney cancer. It causes a tumor on one or both kidneys. It usually affects children, but can happen in adults. Having certain genetic conditions or birth defects can increase the risk of getting it. Children that are at risk should be screened for Wilms' tumor every three months until they turn eight.

Symptoms include a lump in the abdomen, blood in the urine, and a fever for no reason. Tests that examine the kidney and blood are used to find the tumor.

Doctors usually diagnose and remove the tumor in surgery. Other treatments include chemotherapy and radiation and biologic therapies. Biologic therapy boosts your body's own ability to fight cancer.

NIH: National Cancer Institute