How the test is performed

There are several ways to do a skin biopsy. Most procedures can be easily done in outpatient medical offices or your doctor's office.

Which procedure you have depends the location, size, and type of lump or sore. You will receive some type of numbing medicine (anesthetic) before any type of skin biopsy.

Types of skin biopsies include:

• Shave biopsy
• Punch biopsy
• Excisional biopsy
• Incisional biopsy

The shave biopsy is the least invasive of all three techniques. Your doctor will remove the outermost layers of skin. You will not need stitches.

Punch biopsies are most often used for deeper skin spots or sores. Your doctor removes a small round piece of skin (usually the size of a pencil eraser) using a sharp, hollow instrument. If a large sample is taken, the area may be closed with stitches.

An excisional biopsy is done to remove the entire lesion. A numbing medicine is injected into the area. Then the entire lump, spot, or sore is removed, going as deep as needed to get the whole area. The area is closed with stitches. Pressure is applied to the area to stop any bleeding. If a large area is biopsied, a skin graft or flap of normal skin may be used to replace the skin that was removed.

An incisional biopsy takes a piece of a larger growth for examination. The area is injected with a numbing medicine. A piece of the growth is cut and sent to the lab for examination. You may have stitches, if needed. The rest of the growth can be treated after the diagnosis is made.

How to prepare for the test

Tell your health care provider:

• About the medications you are taking (including vitamins and supplements, herbal remedies, and over-the-counter preparations)
• If you have any allergies
• If you have bleeding problems
• If you are pregnant

How the test will feel

There is a brief prick and sting as the anesthetic is injected. Afterward, the area may be tender.

Why the test is performed

Your doctor may order a skin biopsy if you have signs or symptoms of:

• Chronic or acute skin rashes
• Noncancerous (benign) growths
• Skin cancer
• Other skin conditions

Normal Values

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

The test may reveal skin cancers or noncancerous (benign) conditions. Bacteria and fungi can be identified. The test may also reveal some inflammatory diseases of the skin. Once the diagnosis is confirmed with the biopsy, a treatment plan is usually started.

What the risks are

Risks may include:

• Infection
• Scar (keloids)

You will bleed slightly during the procedure. Tell your doctor if you have a history of bleeding problems.

Special considerations

Fluid-filled sores or growths may be examined by skin lesion aspiration instead of skin lesion biopsy.

Review Date: 8/3/2011.

Reviewed by: Kevin Berman, MD, PhD, Associate, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.