Tumors of organs such as kidney, bladder and testis in children differ from adults in terms of their types, behaviors, diagnosis and treatments. In all infants and children with an abdominal mass, different examinations, starting with ultrasound and depending on the findings, age of the child, and other characteristics, are evaluated by oncology study groups, which include people from different specialties specializing in pediatric tumors. Treatment is planned and applied within the framework of existing international or institutes developed protocols. These treatments include surgical removal of the tumor, as well as cancer drugs and radiation treatments, and are applied in certain sequences and protocols. Removal of a mass in the abdomen directly by the surgeon without the above studies and the opinions of other specialists greatly reduces the patient's chance of survival and is no longer an accepted practice in modern medicine.