Skin Biopsy

	Test Overview
	Why It Is Done
	How To Prepare
	How It Is Done
	How It Feels
	Risks
	Results
	What Affects the Test
	What To Think About
	References
	Credits
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A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope.

Several different methods may be used to obtain a skin sample, depending on the size and location of the abnormal area of skin, called a skin lesion. The skin sample is placed in a solution, such as formaldehyde, or in a sterile container if infection is suspected. In each of these procedures, the tissue is processed and then examined under a microscope.

Skin biopsies most often are done to diagnose skin cancer, which may be suspected when an abnormal area of skin has changed color, shape, size, or appearance or has not healed after an injury. Skin cancers are the most common type of cancers.

Early diagnosis of a suspicious skin lesion and skin biopsy can help identify skin cancers and lead to early treatment.

A skin biopsy is done to diagnose a:

• Skin condition (if it is not already clear what the condition is), such as psoriasis.
• Disease, such as skin cancer.
• Bacterial or fungal skin infection.

Before a skin biopsy, tell your doctor if you:

• Are taking any medications, particularly anti-inflammatory medicines such as prednisone. Anti-inflammatory medicines may change the way your biopsy looks under the microscope.
• Are allergic to any medicines.
• Have had any bleeding problems or are taking blood-thinning medicines, such as aspirin or warfarin (Coumadin).
• Are or might be pregnant.

No special preparation is needed before having this test.

You may be asked to sign a consent form. Talk to your health professional about any concerns you have regarding the need for the test, its risk, how it will be done, or what the results will indicate. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?) .

Several different methods may be used to obtain a skin sample, depending on the size and location of the skin lesion. The skin sample is placed in a solution, such as formaldehyde, or in a sterile container if infection is suspected. In each of these procedures, the tissue is then examined under a microscope.

• Shave biopsy. After a local anesthetic is injected, a surgical knife (scalpel) is used to shave off the growth. Stitches are not needed. Any bleeding can usually be controlled with a chemical that stops bleeding and by applying pressure. The biopsy site is then covered with a bandage or sterile dressing. See an illustration of a shave skin biopsy.
• Punch biopsy. After a local anesthetic is injected, a small, sharp tool that looks like a cookie cutter (punch) is placed over the lesion, pushed down, and slowly rotated to remove a circular piece of skin. The skin sample is lifted up with a tool called a forceps or a needle and is cut from the tissue below. Stitches may not be needed for a small skin sample. If a large skin sample is taken, one or two stitches may be needed. Pressure is applied to the site until the bleeding stops. The wound is then covered with a bandage or sterile dressing. See an illustration of a punch biopsy.
• Incision. After a local anesthetic is injected, a piece of the lesion is removed with a scalpel. Stitches are used to close the wound. Pressure is applied to the site until the bleeding stops. The wound is then covered with a bandage or sterile dressing.
• Excision. After a local anesthetic is injected, the entire lesion is removed with a scalpel. Stitches are used to close the wound. Pressure is applied to the site until the bleeding stops. The wound is then covered with a bandage or sterile dressing. If the excision is large, a skin graft may be needed. See an illustration of an excisional biopsy. If cancer is discovered, more surgery will be needed.

You will feel brief stinging pain when the local anesthetic is injected. You should not feel any pain when the skin sample is removed.

Although unlikely, there is a slight risk of infection and a slight risk of persistent bleeding. If you usually form scars after skin injuries or surgery, you could develop a scar at the biopsy site.

After the procedure

Your doctor will give you specific instructions on how to care for your biopsy site. Keep the biopsy site clean and dry until it heals completely.

Your stitches will be taken out 3 to 14 days after the biopsy, depending on the biopsy site. Adhesive bandages should remain in place until they fall off. This usually takes from 7 to 14 days.

The biopsy site may be sore or bleed slightly for several days. Ask your doctor how much bleeding or other drainage is expected. Call your doctor immediately if you have:

• Excessive bleeding or drainage through the bandage. If excessive bleeding occurs, apply pressure to the biopsy site and contact your doctor.
• Increased tenderness, pain, redness, or swelling at the biopsy site.
• A fever.

A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope.

Results from a skin biopsy usually are available in 3 to 10 days.

Your health professional will discuss any abnormal results with you. The significance of these results varies depending on your symptoms and medical history.

Taking medicines, such as anti-inflammatory medicines, those used for fungal infections (antifungal medicines), and corticosteroid skin creams, can interfere with your test or the accuracy of the results.

• If the biopsy contains cancer cells, additional surgery will be needed to remove the cancer completely.
• If the biopsy is done on your face, you may want to have it done by a doctor who specializes in surgical techniques that can minimize scarring, such as a plastic surgeon or dermatologist.
• Further testing may be needed if:
  • A small biopsy does not contain enough cells to make an accurate diagnosis.
  • Cells from the abnormal area weren't included in the sample.

Other Works Consulted

• Handbook of Diagnostic Tests (2003). 3rd ed. Philadelphia: Lippincott Williams and Wilkins.