Wilms Tumor is a type of kidney cancer that primarily affects children, usually between the ages of 3 and 4. It arises from immature kidney cells and is often discovered when a parent notices a swelling in the abdomen or other symptoms like abdominal pain or blood in the urine. Treatment typically involves a combination of surgery, chemotherapy, and sometimes radiation therapy. The prognosis for Wilms Tumor is generally favorable, especially when diagnosed early, with many children achieving long-term remission after treatment.