A skin lesion biopsy is when a small amount of skin is removed so it can be examined. The skin is tested to look for skin conditions or diseases. A skin biopsy can help your health care provider diagnose or rule out problems such as skin cancer or psoriasis. Skin lesions are areas of skin that look different from the surrounding area. They are often bumps or patches, and many issues can cause them. The American Society for Dermatologic Surgery describes a skin lesion as an abnormal lump, bump, ulcer, sore, or colored area of the skin. Chronic wounds that are the site of longstanding inflammation, such as from a burn or a sinus tract, may transform into malignant lesions.

Do not take aspirin or aspirin products 7 days before the biopsy. Do not take blood-thinning products 7 days before the biopsy. Do not take anti-inflammatory products 7 days before the biopsy. Do not take Vitamin E products 7 days before the biopsy. Avoid exercise, bending, straining, swimming, or lifting any heavy objects the day of the biopsy and the day after.

Wash the area once or twice daily with a gentle soap. Please do not scrub or pick at the site. Three to five times a day apply white petrolatum (Vaseline or Aquaphor) to the area.

How the Test is Performed

There are several ways to do a skin biopsy. Most procedures can be done in your provider’s office or an outpatient medical office. It will take about 15 minutes.

Which procedure you have depends on the location, size, and type of lesion. A lesion is an abnormal area of the skin. This can be a lump, sore, or an area of skin color that is not normal.

Before a biopsy, your provider will numb the area of the skin so you don’t feel anything. The different types of skin biopsies are described below.

SHAVE BIOPSY

• Your provider uses a small blade or razor to remove or scrape the outermost layers of skin.
• Your provider will remove all or part of the lesion.
• You will not need stitches. This procedure will leave a small indented area.
• This type of biopsy is often done when skin cancer is suspected.

PUNCH BIOPSY

• Your provider uses a skin punch tool to remove deeper layers of skin.
• The area removed is about the shape and size of a pencil eraser.
• It includes all or part of the lesion. You may have stitches to close the area.
• This type of biopsy is often done to diagnose rashes.

EXCISIONAL BIOPSY

• A surgeon uses a surgical knife (scalpel) to remove the entire lesion. This may include deep layers of skin and fat.
• The area is closed with stitches to place the skin back together.
• If a large area is biopsied, the surgeon may use a skin graft or flap to replace the skin that was removed.
• This type of biopsy is done when a kind of skin cancer called melanoma is suspected.

INCISIONAL BIOPSY

• This procedure takes a piece of a large lesion.
• A piece of the growth is cut and sent to the lab for examination. You may have stitches if needed.
• After diagnosis, the rest of the growth can be treated.

MOHS MICROSURGERY

• This procedure allows skin cancer to be removed with less damage to the healthy skin around it.
• It is most often done to remove skin lesions on the eyelids, nose, ears, lips, or hands.

How to Prepare for the Test

Tell your provider:

• About the medicines you are taking, including vitamins and supplements, herbal remedies, and over-the-counter medicines
• If you have any allergies
• If you have bleeding problems or take a blood thinner drug such as aspirin, warfarin, or Plavix
• If you are or think you might be pregnant

Follow your provider’s instructions on how to prepare for the biopsy.

Why the Test is Performed

Your provider may order a skin biopsy:

• To diagnose the cause of a skin rash
• To make sure a skin growth or skin lesion is not skin cancer

Normal Results

The tissue that was removed is examined under a microscope. Results are most often returned in a few days to a week or more.

If a skin lesion is benign (not cancer), you may not need any further treatment. If the whole skin lesion was not removed at the time of biopsy, you and your provider may decide to completely remove it.

What Abnormal Results Mean

Once the biopsy confirms the diagnosis, your provider will start a treatment plan. A few of the skin problems that may be diagnosed are:

• Psoriasis
• Infection from bacteria or fungus
• Melanoma
• Basal cell skin cancer
• Squamous cell skin cancer

Risks

Risks of a skin biopsy may include:

• Infection
• Scar or keloids

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

Considerations

You will go home with a bandage over the area. The biopsy area may be tender for a few days afterward. You may have a small amount of bleeding.

Depending on what type of biopsy you had, you will be given instructions on how to care for:

• The skin biopsy area
• Stitches, if you have them
• Skin graft or flap, if you have one

The goal is to keep the area clean and dry. Be careful not to bump or stretch the skin near the area, which can cause bleeding. If you have stitches, they will be taken out in about 3 to 14 days.

If you have moderate bleeding, apply pressure to the area for 10 minutes or so. If the bleeding does not stop, call your provider right away. You should also call your provider if you have signs of infection, such as:

• More redness and swelling
• Drainage coming from or around the incision that is thick, tan, green, or yellow, or smells bad (pus)
• Fever

Once the wound heals, you may have a scar.

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