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.
How the Test is Performed
Most procedures can be done in your provider's office or an outpatient medical office. There are several ways to do a skin biopsy. 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 skin so you don't feel anything. The different types of skin biopsies are described below.
- Your provider uses a small blade or razor to remove or scrape the outermost layers of skin.
- All or part of the lesion is removed.
- You will not need stitches. This procedure will leave a small indented area.
- This type of biopsy is often done when a skin cancer is suspected, or a rash that seems to be limited to the top layer of skin.
- Your provider uses a cookie cutter-like skin punch tool to remove deeper layers of skin. The area removed is about the shape and size of a pencil eraser.
- If an infection or immune disorder is suspected, your provider may perform more than one biopsy. One of the biopsies is examined under the microscope, the other is sent to the lab for testing such as for germs (skin culture).
- 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.
- 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 most commonly done when a kind of skin cancer called melanoma is suspected.
- 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.
- This type of biopsy is most commonly done to help diagnose skin ulcers or diseases that involve the tissue below the skin, such as the fatty tissue.
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, clopidogrel, dabigatran, apixaban, or other drugs
- 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
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.
Risks of a skin biopsy may include:
- Scar or keloids
You will bleed slightly during the procedure.
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 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, swelling, or pain
- Drainage coming from or around the incision that is thick, tan, green, or yellow, or smells bad (pus)
Once the wound heals, you may have a scar.
Skin biopsy; Shave biopsy - skin; Punch biopsy - skin; Excisional biopsy - skin; Incisional biopsy - skin; Skin cancer - biopsy; Melanoma - biopsy; Squamous cell cancer - biopsy; Basal cell cancer - biopsy
Dinulos JGH. Dermatologic surgical procedures. In: Dinulos JGH, ed. Habif's Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 27.
High WA, Tomasini CF, Argenziano G, Zalaudek I. Basic principles of dermatology. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 0.
Pfenninger JL. Skin biopsy. In: Fowler GC, eds. Pfenninger and Fowler's Procedures for Primary Care. 4th ed. Philadelphia, PA: Elsevier; 2020:chap 26.
Review Date 8/14/2021
Updated by: Elika Hoss, MD, Senior Associate Consultant, Mayo Clinic, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.