Cuts away dead skin. A doctor removes a corn by first cleaning the skin well. He may numb up the area with a lidocaine-type anesthetic if it looks like there may be pain involved. Then, he shaves away the dead skin forming the corn and callus, using a sharp scalpel blade.
Corn. He/she can shave it or perform surgery to remove underlining bone that causes the corn to develop. Like hammertoe surgery.