Atlas of Primary Care Procedures, 1st Edition

Dermatology

11

Shave Biopsy

Shave biopsy is one of the most widely used procedures performed in primary care practice. The technique is used to obtain tissue for histologic examination and is useful for removing superficial lesions in their entirety. Pedunculated lesions above the skin surface are particularly well suited for this removal technique, but flat lesions that are high in the dermis and do not extend beneath the dermis can also be removed by shave technique. Horizontal slicing is performed at the level of the dermis, avoiding injury to the subcutaneous tissues. Cosmetic results generally are good, with the least noticeable scars occurring when lesions are removed from concave surfaces such as the nasolabial fold.

Four techniques are commonly employed for shave biopsy. A no. 15 scalpel blade held horizontally in the hand can provide good control of depth. The ease of the scalpel technique makes it a frequent choice by inexperienced physicians. Horizontal slicing with a flexed razor blade is a time-honored method for shave biopsy. This technique is used less frequently because of the potential for injury from the large, exposed cutting surface. Scissors (e.g., iris scissors) can be effectively used to remove elevated lesions. Scissors removal of flat lesions can be more difficult. Radiosurgical loop removal is effective, although novice practitioners tend to create deeper, “scoop” defects in the dermis beneath the lesion being removed.

Shave biopsy is performed deep enough to remove the lesion but shallow enough to prevent significant damage to the deep dermis. The deeper the damage in the skin, the more likely scar formation will leave a noticeable, hypopigmented scar. If a scoop defect is created, the edges can be feathered (i.e., smoothed) to blend the color change into the surrounding skin (see Chapter 20). Depressed scars can result after this technique, especially from areas where there is extensive muscle tension on the skin, such as the chin or perioral areas.

Many physicians recommend not performing shave biopsy on pigmented lesions. If a lesion should turn out to be a melanoma on biopsy, using a technique that cuts through the middle of the lesion can create major problems for determining depth, prognosis, and therapy for the lesion. Some clinicians argue that the shave technique can be performed on melanomas and that the old adage of not shaving a pigmented lesion can be dropped. Most still recommend caution, and it is our recommendation that excisional biopsy (see Chapter 12) should be used for any pigmented lesion that could potentially represent a melanoma.

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INDICATIONS

• Lesions amenable to shave excisional technique include acrochordons (i.e., skin tags), angiomas, fibromas, basal cell carcinomas (i.e., well-defined, small, primary and not recurrent, and in low-risk sites), dermatofibromas, keratoacanthomas, cutaneous horns, molluscum contagiosum, nonpigmented nevi (e.g., intradermal nevi), papillomas, warts, syringomas, venous lakes, cherry angiomas, stucco keratoses, seborrheic keratoses, actinic keratoses, rhinophymas, sebaceous hyperplasia, porokeratosis, neurofibromas, and dermatosis papulosa nigra.

RELATIVE CONTRAINDICATIONS: LESIONS BEST CONSIDERED FOR ALTERNATE TECHNIQUES

• Pigmented nevi (pathology specimen should be full thickness of the skin in the event the lesion is a melanoma)
• Skin appendage lesions (e.g., cylindromas, epidermoid cysts)
• Subcutaneous lesions (pathology often missed by shave technique)
• Epidermal nevi (removal requires full-thickness excision)
• Lesions on sites with extensive muscle tension on the skin (e.g., chin, perioral sites)

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PROCEDURE

Small, pedunculated lesions can be removed easily with the shave technique. Pictured is a small angioma that appears on a stalk. The skin is stretched with the nondominant hand, and the lesion is removed with sharp iris scissors. Small lesions can be removed without local anesthesia if the pain receptors within the skin are stretched.

PITFALL: The scissors must be flush with the skin surface to prevent leaving a residual stump, but no extra skin should be included within the scissor blades to prevent unintentional cutting of surrounding skin.

For removal of a flat (sessile) lesion, local anesthetic is placed beneath the lesion in subdermal and intradermal locations (Figure 2A). The fluid raises the lesion upward, allowing easier removal (Figure 2B). Administration of local anesthetic thickens the skin, making it less likely that the shave will penetrate the dermis into the subcutaneous fat (Figure 2C).

PITFALL: Unintentional penetration into the fat (i.e., yellow fat in the base of the wound) should prompt transforming the biopsy site into a sterile surgical wound. The wound should have the edges incised vertically, and the wound should be closed with sutures.

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Lesion removal can be facilitated by elevating and squeezing the surrounding skin.

A no. 15 blade is held horizontal in the dominant hand while the nondominant hand stabilizes surrounding skin (Figure 4A). The blade is brought across the base of the lesion (Figure 4B) with a straight movement or with a back-and-forth movement (Figure 4C).

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Biopsy can be performed with a razor blade held in the hand, with tension applied to the two sides to create some curvature. The sharp surface is brought beneath the lesion for removal within the dermis.

PITFALL: The large, exposed, cutting surface of the razor blade and the hand tension required to maintain curvature of the blade provide great potential for injury. Some surgeons no longer advocate use of razor blades for shave biopsy because of this potential for injury.

Radiosurgical loop excision can be used to perform a shave biopsy. The lesion is grasped and elevated within the radiosurgical loop using Adson forceps (Figure 6A). The loop is activated and moved across the base of the lesion (Figure 6B.) The radiosurgical current can be set to provide hemostasis to the wound base.

PITFALL: Novice physicians tend to scoop with the loop. The loop must be brought under the lesion horizontally, and the lesion must not be excessively elevated to prevent large scoop defects from this technique.

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The wound base can be treated with ferric subsulfate (i.e., Monsel's solution) for hemostasis. Ferric subsulfate should be applied to a dry wound bed; the blood must be wiped away with the solution applied immediately thereafter. Antibiotic ointment and a bandage are then applied.

PITFALL: Ferric subsulfate can rarely produce permanent discoloration or “tattooing” of the skin. Consider using a 35% to 85% aluminum chloride solution on the faces of fair-skinned (light-complexioned) individuals to avoid this complication.

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CODING INFORMATION

The following coding information is for shaving of epidermal or dermal lesions, including lesions on mucous membranes (MM). The codes are for single lesion removal.

INSTRUMENT AND MATERIALS ORDERING

Number 15 scalpel blades, razor blades, scissors, and hemostatic agents such as ferric subsulfate are available from surgical supply houses or the resources listed in Appendix A. A suggested anesthesia tray that can be used for this procedure is listed in Appendix G. Skin preparation recommendations appear in Appendix H. Radiosurgical instruments and machines are described in Chapter 20.

For practitioners wishing to perform shave biopsy with a razor blade, the disposable DermaBlade (Personna Medical, American Razor Company, Stauton, VA) enhances safety by allowing the operator to grasp the sure-grip teeth to the sides instead of directly handling the blade.

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