A punch biopsy is done to remove a skin growth (lesion). A sharp tool called a skin punch is used. The tool works like a tiny cookie cutter. The doctor gives a local anesthetic to numb the area. Then the tool is placed over the growth, pushed down, and slowly rotated to remove a circular core of skin. The biopsy area is then covered with a bandage.

After the growth is removed, a doctor trained to look at tissue samples (pathologist) will check it for cell changes, such as cancer. The pathologist also may do tests to detect an infection caused by a virus, a fungus, or bacteria.