For many physicians, surgery is an option for a kidney mass at clinical stage 1, according to the American Urological Association. At this point, the mass is less than 7 centimeters. About 20 percent of stage 1 masses are benign.
Because the stage 1 mass is small, and because even a malignant stage 1 tumor is usually not aggressive, some doctors recommend active surveillance for these patients, explains the AUA. Surgical options include the removal of the entire kidney, or radical nephrectomy, which can be a traditional open procedure or a laparoscopic procedure. The surgeon can also use variants on a partial nephrectomy.