The tumor is entered through surgical procedure and the inside is removed, leaving behind microscopic and macroscopic cancer cells. This is most commonly used for for benign tumors. This approach prevents surrounding tissues from being damaged while removing most of the tumor. For benign aggressive bone tumors additional steps may be taken such as shaving the walls of the tumor cavity with a midas rex burr (high speed dental drill) and using liquid nitrogen (cryosurgery) or the argon laser beam to get rid of the microscopic cells and minimize the chances of the tumor coming back.