If you agree to take part in this study, after you have been given the anesthetic for your surgery, your uterus will be examined to locate the tumor(s). After the tumor(s) are located, they will be injected with a radioactive substance called Tc-99m sulfur colloid. The tumors will then be injected with a dye called isosulfan blue or methylene blue, which is used to turn the sentinel node blue.