Wilms' Tumor

Wilms' tumor is a type of childhood cancer that occurs in the kidneys, a pair of kidney-bean shaped organs -- located above the waist on either side of the spine -- that filter and clean blood and produce urine.

Wilms' tumor also is called nephroblastoma. "Nephro" means kidney, "blast" means primitive cell and "oma" means tumor. It is the fifth most common childhood cancer. About 400 children in the United States are diagnosed with Wilms' tumor each year. The disease, which affects boys and girls equally, can occur at any age between infancy and 15 years, although the tumor usually is diagnosed by age 3.

Generally, the condition causes a painless swelling in the abdomen and is discovered while bathing, dressing or changing the diapers of your child. Some children may have bloody urine, abdominal pain, loss of appetite, fatigue or weight loss.

For more information or to make an appointment, please call:
Children's Cancer and Blood Disease Program (415) 476-3831

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007