How is a biopsy performed?

Editor’s Note: A skin biopsy is routinely performed in the dermatologist’s office.


✽    Tell your doctor if you have any allergies to medications, and especially if you have had any reactions to local anesthetics, such as lidocaine or novocaine, or to iodine cleaning solutions, such as Betadine.44.

✽    Inform your doctor if you are taking any medications, including over-the-counter drugs, street drugs, or herbal or nutritional supplements.

✽    Tell your doctor if you have any bleeding problems or if you are pregnant.

✽    You may be asked to change into a gown or remove an article of clothing so that the area of suspect skin can be more easily seen and removed.

How biopsy is performed

✽    It is crucial that the site of a biopsy is chosen carefully, or the pathological diagnosis could be incorrect or misleading.

✽    The site of the skin biopsy may be cleaned with an iodine-type solution, with alcohol, or with a sterile soap solution.

✽    A marker may be used to outline the edges of the skin sample.

✽    For some biopsies, a surgical drape is used to cover the area around the biopsy and the doctor will wear a mask, gown, and gloves.

✽    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.

✽    After the skin has been cleaned, sterile towels are placed around the area.

✽    Do not touch this area once it has been cleaned and prepared.

✽    A local anesthetic, usually lidocaine, is injected into the skin to make it numb. You will feel a brief prick and stinging sensation as the medicine is injected. After the skin is numb, your doctor performs the biopsy.

After the Skin Biopsy Procedure

✽    Your doctor will put a bandage over your biopsy site. Keep this bandage dry. You may be advised to wash the wound, apply antibacterial ointment or petrolatum (Vaseline) and change the bandage daily.

✽    If you have stitches, you need to keep the area clean and dry. Follow instructions regarding when and how to wash the wound. Stitches on the face are removed in 5-8 days. Stitches placed elsewhere on the body are removed in 7-14 days. Adhesive strips are left in place for 10-21 days.

✽    If you have pain at the biopsy site, talk with your doctor about medication to relieve it. In most cases, discomfort is minimal and requires nothing more than an over-the-counter pain medication. 

✽    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: (1) excessive bleeding or drainage through the bandage, (2) increased tenderness, pain, redness, or swelling at the biopsy site or (3) a  fever.

Next Steps after Skin Biopsy

✽    Your doctor needs to see you again to remove the stitches and to give you the results of the pathology report. If no stitches are placed, he may ask you to get in touch by phone so he or she can discuss the results for you.

Sending the sample to a dermatopathologist

✽    The clinician should ensure that the pathology request form includes basic patient information (including age and identification details), the site and type of biopsy, and time and date. “Left” and “right” are best written out in full to avoid mistakes

✽    It is crucial for the pathologist to be provided with clinical information and a range of possible diagnoses. Clinical information should include a description of the duration, symptoms and a dermatologic description.

Editor’s Note: This is where it is important for a dermatologist who suspects pityriasis rubra pilaris to share that information with the dermatopathologist.

✽    The sample pot should be labelled with patient identification details, the body site of the biopsy, time and date, and checked against the request form for consistency. When multiple biopsies are taken roman numbers are best used to match the request forms with their corresponding sample pots.

✽    The tissue that is removed is sent to the laboratory for analysis by a dermatopathologist.

Sources used to prepare this article