A shave biopsy is a surgical technique performed when a skin lesion cannot be diagnosed on the basis of a clinical exam alone. A shave biopsy samples a portion of the superficial layers of the skin and therefore is minimally invasive.
When is a Shave Biopsy Performed?
It is used to diagnose precancers such as actinic keratoses and superficial skin cancers such as squamous cell carcinoma and basal cell carcinoma. It also used when a practitioner is uncertain of the diagnosis of any particular lesion. Shave biopsies are usually performed for raised lesions, lesions with a stalk or when a deep sampling of the skin is not necessary.
Occasionally the practitioner may need to perform a deeper biopsy and will use the saucerization technique. The goal is usually to 1) remove the entire skin lesion, and 2) allow the pathologist to examine the edges of the specimen to see if it has been completely removed. The saucerization technique can be done for pigmented skin lesions such as a growth suspicious for melanoma, to allow the accurate measurement of the depth of the lesion.
What Are The Steps in a Shave Biopsy?[1,2]
- The biopsy site is cleaned using alcohol or other anti-septic solutions.
- The site is anesthetized using an injectable numbing medications, such as lidocaine. Epinephrine is typically mixed with lidocaine to help constrict the blood vessels in the skin to decrease bleeding associated with the procedure; this also allows the numbing medication to have a longer effect.
- The biopsy may be performed using a scalpel or another type of sterile blade. The specimen is usually placed in a fixative solution and sent to the laboratory where a doctor trained in pathology performs an evaluation of the processed skin lesion under the microscope.
- Any small amount of bleeding is usually stopped using a chemical solution such as aluminum chloride, Monsel’s solution or by electrocautery (heat).
- The biopsy site is often covered with a petroleum based ointment and covered with a bandage.
- The wound is usually left to heal on its own without sutures.
What Are Some Risks Associated with a Shave Biopsy?
Though a shave biopsy is a minimally invasive outpatient procedure, it may carry the following risks:
- Pain, typically only for a few short seconds when the numbing medication is being injected
- Bleeding, which is usually minimal for superficial procedures of the skin. The risk of bleeding is higher in people who are taking blood thinners or have medical conditions that may prevent their blood from clotting efficiently.
- Skin infections, though the overall rate of infection in outpatient skin procedures is only between 1-2%.[3,4]
- Scarring: Both atrophy (depressed) or hypertrophic (elevated) scars may form.
- Temporary or permanent change in the color of the skin at the biopsy site.
- Rarely, shave biopsies may cause temporary or permanent nerve damage (change or loss of skin sensation), or hair loss at the biopsy site.
What Is The Wound Care After a Biopsy?
The biopsy site is typically left alone (without getting the site wet) for 24 hours. Then the biopsy site is cleaned with soap and water daily and covered with a petroleum based bandages or topical ointment/cream for about 7 days. Using a topical ointment containing an antibiotic is typically not recommended because of the risk to develop a skin allergy with certain topical antibiotics. In a randomized controlled trial, white petrolatum was shown to be a safe wound care ointment for outpatient surgery and decreases the risk of allergic skin reactions and bacterial infections. Using topical antibiotic ointments does not lower post-operative skin infections any more than petroleum-based ointment, yet is associated with higher allergic skin reactions, and therefore often avoided. Additionally, leaving the wound open to air or allowing it to dry may slow down the healing process and may worsen the appearance of the final scar.
It is important to understand that each practitioner may have a slightly different way to manage the biopsy site. These differences may have to do with the patient (e.g. tendency to bleed), the location (e.g. hairy scalp versus the groin), the skin lesion sampled and other such considerations. Generally accepted principals are discussed here along with the evidence available to support these practices.