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This procedure is done in a doctor's office, often by a dermatologist. The doctor begins by injecting a local anesthetic near the biopsy site. Although the injection usually stings for a second, the rest of the procedure is painless. Depending on the size of the lesion, one of two methods will be used to remove or sample it.
For small lesions and tissue samples, your doctor might do a punch biopsy, in which he or she places an instrument shaped like a straw with a sharp end against your skin and twists it. The sharp end works like a cookie cutter to slice a small circle from the top layer of skin. The doctor lifts the tissue away with tweezers. A single stitch closes the opening in the skin.
Larger lesions and tissue samples are removed with an excisional biopsy. In this case, the doctor uses a blade to cut an oval opening around the area. The doctor will stop any bleeding with a cauterizer, a wand-shaped instrument that uses an electric current to seal the ends of bleeding blood vessels. You'll also need stitches to close the incision.
With both types of biopsies, the skin sample is then given to a pathologist and examined under a high-powered microscope. You'll probably be able to go home right afterward.
For skin biopsies that are being tested for melanoma, the most serious form of skin cancer, and your doctor will try to remove the entire area that looks abnormal. That way, the biopsy will not only determine if the lesion is malignant, it might also cure the cancer. The sample will be examined under a microscope to make sure the whole cancer has been removed. You might need additional skin surgery if the examination shows that the cancer extended to the margins of the skin sample.