The Shave Biopsy

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9 The Shave Biopsy

The shave biopsy is one of the most useful approaches for obtaining tissue for diagnostic purposes and for the removal of benign surface neoplasms. It is especially fast, easy, and effective when the lesion is raised above the skin surface. The shave biopsy is also valuable for diagnosing many cutaneous malignancies, including basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs). It is also an effective tool for removing benign lesions such as intradermal nevi and seborrheic keratoses. After a shave biopsy, hemostasis is easily obtained with aluminum chloride. The surface is allowed to heal naturally, and no sutures are needed. The excision site usually heals well with a good cosmetic result.

Contraindications

There are no contraindications for shave biopsy based on location of the lesion. The use of a shave biopsy to diagnose a melanoma is controversial with a wide range of opinions. A superficial shave biopsy of a suspected melanoma runs the risk of losing important depth information used for staging and margin determination. However, if the melanoma is thin and the shave biopsy gets below the tumor, then nothing is lost. On the other hand, if a punch biopsy is performed of a large lesion and the punch misses the area with melanoma, this false-negative result can lead to missing the diagnosis of the melanoma. Although doing a complete full-thickness biopsy of a small suspected melanoma is optimal, this may be too deforming for a large superficial pigmented lesion on the face that might possibly be lentigo maligna melanoma (LMM) but appears more consistent with a solar lentigo (Figure 9-7). A broad scoop shave biopsy of LMM (Figure 9-8) may give a better tissue sample than one or more punch biopsies and will not cause the cosmetic deformities of a large full-thickness biopsy. It is also common practice to use a broad scoop shave to remove an atypical mole suspected of being a dysplastic nevus.

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FIGURE 9-7 Solar lentigo.

(Copyright Richard P. Usatine, MD.)

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FIGURE 9-8 Lentigo maligna melanoma.

(Copyright Richard P. Usatine, MD.)

In reality, the biopsy type is based on suspected diagnosis, size, location, patient preferences, and time considerations. It is better to diagnose a melanoma by shave biopsy than to lose a patient with melanoma to follow-up because you did not have the time to do an elliptical biopsy.

Disadvantages of A Shave Biopsy

As with the advantages of the shave biopsy, the disadvantages can also be categorized into those for the clinician and those for the patient. Disadvantages for the clinician include the following:

 

For the patient, the disadvantages of shave biopsy include the following:

 

A superficial shave biopsy should heal with little to no indentation of the skin.4 Deep-shave biopsies are more likely to leave an indentation. Persistence rates of melanocytic lesions for shave biopsy range from approximately 13% to 28%.5 Persistence does not always translate into regrowth. If regrowth does occur, it is important to have access to the original pathology report to avoid overdiagnosing a benign regrowth as a melanoma (pseudomelanoma). Methods useful to differentiate pseudomelanoma from melanoma include accurate clinical records of prior biopsy sites along with evidence of scarring within the current biopsy.5

Equipment

The minimum equipment necessary for a shave biopsy is a sharp blade (razor blade or No. 15 scalpel), a 3-mL syringe and needle for local anesthesia, and cotton-tipped applicators (CTAs) and aluminum chloride for hemostasis. It is handy to have a forceps to hold the lesion during the shave procedure or to transfer the tissue into the biopsy container. (The end of a CTA can also be used to do this transfer in many cases.) A surgical marking pen can be useful and is best used before administering the anesthesia.

The Personna DermaBlade is an excellent razor blade for shave biopsies. The blue plastic handle makes it easy and safe to grip the sharp razor blade and control the blade for an accurate and precise shave excision. The cost of the disposable DermaBlade is about the same as a standard disposable No. 15 scalpel. Other options include the Personna or Wilkinson double-edge razor blade. The Personna (or Personna Plus with Teflon coating) double-edge blade is very sharp and can be broken in half for easy use (Figure 9-9). Although these do not come in sterile packaging, they can be safely used for shave biopsies without using the autoclave. At approximately 15 cents per cutting blade (30 cents per two-sided blade), these are the most cost-effective tool for shave biopsies. They can be broken in half within their paper container to avoid cutting your hand prior to use. It might take some more time to get used to the bare blade, but once you have mastered its use, you will find this type of low-cost blade to be sharp and effective.

Miltex produces a BiopBlade flexible scalpel for shave biopsies. Its design is similar to that of the DermaBlade, using a single-edge razor blade with a plastic bendable handle. It is currently more expensive than the DermaBlade and has no advantages over the DermaBlade. The plastic handle can snap in half if the blade is bent incorrectly. The Personna single-edge razor blade is too rigid for shave biopsies. All of these blades (Figure 9-10) are available for purchase through Delasco (www.delasco.com) and some can be purchased through other suppliers.

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FIGURE 9-10 Equipment used to perform a shave biopsy.

(Copyright Richard P. Usatine, MD.)

Shave Biopsy: Steps and Principles

Three critical steps in the shave biopsy include:

Preoperative Measures

After determining that the shave technique is the best method for the patient, obtain informed consent. (See Appendix A for an informed consent form titled Disclosure and Consent: Medical and Surgical Procedures.) By visual inspection and palpation, determine the likely depth of the lesion and plan the depth of your biopsy based on the probable diagnosis and your physical exam.
Inject local anesthesia. Use a 30-gauge needle with approximately 2 to 3 mL of 1% lidocaine and epinephrine (buffer the lidocaine for less pain; see Chapter 3, Anesthesia). Start with the needle under the lesion (greater depth is less painful) and then give the last amount of anesthesia closer to the skin surface. If the lesion is flat, consider raising the lesion some with the anesthesia (Figure 9-12A).

Cutting the Shave Biopsy

Snip Excision with Scissors

Another variation of the shave excision for small raised lesions is the snip excision performed with sharp scissors (Figure 9-14). Anesthesia and hemostasis are executed in the same manner as for the other types of shave excision. The only difference is that the lesion is snipped off with sharp scissors rather than shaved with a blade. Lesions particularly amenable to snip excision are skin tags, small warts, and polypoid nevi. We recommend using a good pair of sharp iris scissors (straight or curved). Small lesions may be snipped without anesthesia, but larger lesions should be anesthetized with 1% lidocaine and epinephrine. The lesion is grasped with forceps and cut at the base with the scissors. The crushing effect of the scissor on the soft tissue helps to prevent bleeding. Additional hemostasis can be achieved with aluminum chloride or electrosurgery.

Electrosurgical Shave

A loop electrode may be used to perform an electrosurgical shave (Figure 9-15). The loop electrode can be used to feather the remaining tissue and sculpt a nice result. One downside is that there will be burn artifact on the biopsy specimen. Also, if the lesion is caused by human papillomavirus (HPV), there is a very small risk of transmission of the HPV by the plume. Whether the instrument is set on cut only or cut and coag, it is important to not use too much power, which can result in unnecessary tissue destruction leading to increased scarring. (Also see Chapter 14, Electrosurgery.)

Scoop Shave (Deep-Shave Saucerization Technique)

A saucerization technique involves the removal of the lesion using a deep shave or scoop technique with 1 to 2 mm of surrounding normal skin laterally and extending into the deep dermis (Figure 9-16).5 For thin and small-diameter melanocytic lesions, a scoop shave can remove the entire lesion.5 The National Comprehensive Cancer Network (NCCN) recommendations suggest deep-shave biopsies be used when the index of suspicion for melanoma is low.5 However, a deep-shave biopsy can also be performed for suspected melanoma in certain circumstances (see Chapter 8, Choosing the Biopsy Type).

It is easier to do a scoop shave with a DermaBlade or other razor blade than a scalpel. Start by marking the area to be cut, including the planned margin. If the lesion is suspected to be a dysplastic nevus, mark a 2-mm margin around the edge of the pigment. Direct the blade downward at an angle of 30 to 45 degrees with the skin to get underneath the pigment. Continue the shave straight across the base and come upward, leaving another 2 mm from the edge of the pigment. The scoop shave should go into the deep dermis. If a full-thickness biopsy is to be performed into the subcutaneous fat, it is suggested that this be performed with an elliptical excision and closed with sutures. If a few small fat globules are visible at the base of the shave, the area can heal well by second intention.

A pigmented lesion on the back suspected to be a superficial spreading melanoma can be easily and safely biopsied with a deep-shave approach (Figure 9-17). The scoop shave using a razor blade of the thickest pigmented area produces a good specimen for diagnosis of melanoma. (Breslow’s thickness of 0.6 mm was obtained in Figure 9-7.) In Figure 9-17 note how the shave went completely under the pigment and the depth information was not lost. If pigment were to be found below the shave, a deeper shave or full-thickness incisional biopsy could be performed of the remaining lesion.

When performing a deep scoop shave to remove a nonmelanoma skin cancer, it is appropriate to cut down deep enough so that small fat globules will be visible (Figure 9-18). If all margins are clear this can serve as the definitive treatment for less aggressive nonmelanoma skin cancers such as superficial or nodular BCCs (not sclerosing) or SCC in situ. This method is not recommended for skin cancers larger than 2 cm or in danger areas around vital structures. Definitive treatment for invasive SCC and melanoma should include a full-thickness excision with appropriate margins. As with all skin cancers, regular examinations need to be done to investigate for recurrence and new cancers. A shave excision of any depth should never be the definitive surgery to treat a melanoma.

Stabilization Techniques

Lesions should be stabilized during the shave biopsy to maximize the control during cutting. In Figure 9-19, forceps are used, and in Figure 9-20, the skin is pinched because the lesion is very flat. Note how the fingers of the nondominant hand are kept in the biopsy area to provide gentle countertraction and to stabilize the tissue. On certain areas of thin skin near vital structures such as the eye or hand, it may be necessary to pinch and elevate the surrounding skin with one hand while doing the biopsy with the other. The end of a CTA is useful for preventing the lesion from flipping over near the final portion of the cut (Figure 9-21). Raising a flat lesion with anesthetic just prior to excision can help stabilize the lesion but may increase the risk of indentation. Regardless of which method is used, it is important to not pull up on the lesion to avoid creating an unintended deep indentation.

Less Than Optimal Outcomes

Infections are rare complications of shave biopsies.

Expected but less than optimal outcomes that often occur after shave biopsies include the following:

Serious complications are extremely rare after a shave biopsy.

After shave biopsy, erythema may persist for months, and hypopigmentation may be permanent in some individuals. In the case of melanocytic nevi some will regrow after removal by this technique. In nevi with hair, the hair may regrow if the nevus is excised with a shave biopsy alone. This type of nevus may be best removed with a deeper elliptical excision. Alternatively, the hair follicles remaining after a shave biopsy may be destroyed with electrosurgery.

Cosmetic Results

Gambichler et al.4 examined the cosmetic outcome of macular melanocytic lesions utilizing the deep-shave biopsy technique with a razor blade followed by chemical hemostasis. During routine skin cancer screening 45 patients with 77 macular melanocytic nevi were prospectively recruited. Histologically, 88% of the melanocytic lesions were described as completely excised and 60% were diagnosed as atypical melanocytic nevi. At 6 months, 56 sites were available for evaluation and mild hypopigmentation was observed in 52%, hyperpigmentation in 32%, and erythema in 23%. Recurrent nevi occurred in 13% at 6 months. The evaluation of the cosmetic outcome by the patients was better than the evaluation by the physician.4

In another prospective study, shave excision of 204 common acquired melanocytic nevi was performed.6 Mid-dermal shave biopsies were performed using a No. 15 blade followed by gentle electrocoagulation. Three months after surgery, cosmetically excellent results occurred in 33% of the patients, acceptable results in 59%, and poor results in 8% as assessed by two dermatologists. The likelihood of having an imperceptible scar was significantly greater in lesions excised from the face. Of 192 patients surveyed, 98% stated that “the scar looked better than the original mole” and would undergo the procedure again. Clinical and dermatoscopic recurrences were observed in 19.6% of the scars.6

Our experience is that shave excisions heal with less scarring than electrodesiccation and curettage (ED&C), which often leads to hypertrophic scarring.

Additional Examples for Shave Biopsy

Basal Cell Carcinomas

In Figure 9-27, a shave biopsy is preferred on the nasal ala rather than a punch biopsy. After the diagnosis was made, this patient was referred for Mohs surgery. One study showed that specimens from punch and shave biopsies of suspected BCCs produced equivalent diagnostic accuracy rates: 80.7% and 75.9%, respectively. Either biopsy technique is appropriate for a BCC.7 The woman in Figure 9-28 has had multiple BCCs and had chosen to have a shave excision of a small BCC on her cheek. A previous biopsy had proven the diagnosis and she wanted less invasive surgery than a full elliptical excision. The margins were clear and the area healed with minimal scarring.

Psoriasis

Psoriasis is frequently a diagnosis made on clinical appearance and history only. Sometimes psoriasis presents in an atypical pattern and a biopsy is needed to make the diagnosis. The patient in Figure 9-30 developed a rash on his penis and had no other skin findings. A shave biopsy of the lesion allowed the diagnosis of psoriasis to be made. While a punch biopsy would have provided adequate tissue, greater risks are involved in a punch biopsy of the penis. Having a definitive diagnosis was helpful to guide treatment of this disturbing eruption.

Coding and Billing Pearls

The shave procedure is either used as a form of biopsy and billed under the biopsy codes or used to fully excise a lesion that is benign and then billed under the shave excision codes. It can be confusing sometimes to decide whether the procedure is a “biopsy” or “excision.” Clear-cut examples of shave biopsies include sampling a possible skin cancer or removing a piece of skin to determine the cause of an unknown rash. Shave excisions are those procedures that are used to remove a benign nevus, a seborrheic keratosis, or another benign lesion. The intent is to excise the whole lesion, and even though it is recommended that all pigmented lesions be sent for confirmatory pathologic diagnosis, the primary reason for the procedure was not a “biopsy” but a removal of the lesion itself. Make sure that the documentation is consistent with the procedure that is billed. If the shave is done as a biopsy, call it a shave biopsy, but if the shave is done as an excision, call it a shave excision or just an excision.

CPT codes and fees for shave biopsies are summarized in Table 38-7 of Chapter 38, Surviving Financially. Note that, although these codes cover shave biopsies, they also cover biopsies done by punch or curette. The codes are based on location only and not on the size of the biopsy or lesion. The codes are also independent of whether the lesion turns out to be benign or malignant, so there is no need to wait for the pathology result to submit the bill.

Selected CPT codes and fees for shave excisions are provided in Table 38-10 of Chapter 38. These codes are based on size and location, so it is crucial to measure the lesion before excising it. Do not estimate the size later because estimates are usually rounded to the nearest centimeter and the reimbursement goes up 0.1 cm above each rounded number (e.g., payment is greater for a shave excision of a 1.1-cm lesion than a 1.0-cm lesion). Location also matters but these codes are generally used for benign lesions rather than skin cancers. Most skin cancers will be excised deeply or destroyed and there are codes specific to these procedures on malignant lesions.