Wilms Tumor

Wilms tumor is a rare kidney cancer that usually affects children under the age of 5. Wilms tumor can occur in just one kidney, or both at the same time. The kidneys are located in the back wall of the abdomen; their main job is to filter blood and rid the body of excess water, salt, and waste. Wilms tumors usually become quite large before they are noticed and are normally found before they spread to other organs.