A skin biopsy is a small sample of skin that is examined under the microscope to help diagnose a disease. Reasons to take a biopsy include evaluating a puzzling skin problem, removing or sampling a skin change suspicious for cancer, or removing a suspicious mole. Two types of skin biopsies are commonly done—a shave biopsy and a punch biopsy. A shave biopsy is performed with a sterile razor-like tool that is used to cuts off a superficial piece of the skin. The skin is then usually covered and left to heal itself.
A punch biopsy uses a small, specially designed punching tool shaped like a miniature “cookie cutter.” This punch is usually deeper than a shave and lets the examining physician see farther down into the skin. This is especially helpful if the skin is thick or the changes are deep in the skin. Because a punch biopsy is deeper than a shave biopsy, the punch is usually closed with small stitches or sutures. These sutures may dissolve in the skin or they may need to be removed.
Different sutures are used and are left in for varying lengths of time depending on the thickness of the skin and the movement in the area. It is important to have a suture removed at the correct time to prevent scarring or reopening of a wound. For all biopsies, the skin is pre-pared by careful cleaning to reduce the risk of infection and is numbed to minimize discomfort. After a biopsy is taken, the skin sample is preserved, cut into thin slices, and stained with special dyes to see differences in the tissue under the microscope.
The biopsy results may return in 1 to 6 weeks, depending on the laboratory involved. If a result is still unclear or confusing, it may be sent to additional physicians for analysis. The results of a biopsy are usually formally reported in your medical chart at the doctor’s office. When the results are available, you may consider keeping a copy with your personal medical record in case you see a different physician in the future.