The Punch Biopsy

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10 The Punch Biopsy

The punch biopsy is an easy method for removing a round full-thickness skin specimen. It is often used to diagnose skin lesions of uncertain etiology. The main advantage of the punch biopsy over the shave technique is that it yields deeper tissue with preserved architecture for pathologic evaluation. It is also easier to perform on flat lesions for clinicians who have not mastered the art of the shave biopsy for lesions that are not elevated.

Flat lesions that are amenable to punch biopsy include inflammatory skin conditions such as drug eruptions, dermatoses, psoriasis, and cutaneous lupus (Figure 10-1). Infiltrative skin conditions such as sarcoidosis and granuloma annulare also can be diagnosed with a punch biopsy (Figure 10-2). In addition, a punch biopsy may be used to diagnose all types of skin cancers including melanoma and cutaneous lymphomas (Figure 10-3).

FIGURE 10-1 Cutaneous lupus (discoid lupus) with hypopigmentation and skin atrophy. The best method for diagnosis is a 4-mm punch biopsy.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-2 Cutaneous sarcoidosis on the face of a black woman. Although this is likely to be sarcoidosis by its appearance, a 4-mm punch biopsy was used to confirm the diagnosis.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-3 Mycosis fungoides. A previous biopsy years before was read as atopic dermatitis. When the skin disease did not respond to topical steroids and subsequently worsened, a new 4-mm punch biopsy detected cutaneous T-cell lymphoma.

(Courtesy of Debra Henderson, MD.)

A punch biopsy is one option in the diagnosis of melanoma if the entire lesion is large, making it too difficult to remove the whole lesion at the time of biopsy. In this case, the diagnostic yield will generally be best if a biopsy is performed on the darkest, most elevated, and/or most suspicious areas (Figure 10-4). Using a dermatoscope may help identify a suspicious area for the punch biopsy (see Chapter 32, Dermoscopy). If the suspicion for melanoma is high, excising the entire lesion is preferred, when possible, to improve the diagnostic yield. There are also times when a broad scoop shave may provide better tissue for the pathologist. The highest risk of using a punch biopsy to diagnose a melanoma is the risk of a false-negative result. If the lesion remains suspicious for melanoma and a punch biopsy was performed with a negative result, the remainder of the lesion should be excised for histology (see Chapter 8, Choosing the Biopsy Type).

FIGURE 10-4 A lesion suspicious for melanoma on the arm. It was too large to be fully excised easily, so a punch biopsy was performed of the darkest most raised area and the lesion was determined to be a superficial spreading melanoma with a 0.25-mm depth. The full melanoma was excised with 1-cm margins and the depth was unchanged when the full lesion was evaluated histologically.

(Courtesy of Eric Kraus, MD.)

Indications

Punch biopsy can be used to diagnose any skin condition or disease. The following are amenable to punch biopsy for diagnosis:

• Bullous diseases (Figure 10-5)

• Cicatricial alopecias (Figure 10-6)

• Inflammatory skin disease such as dermatoses, psoriasis, and vasculitis

• Infiltrative diseases such as cutaneous sarcoidosis and granuloma annulare

• Melanoma and cutaneous lymphomas (including nail melanoma)

• Oral lesions such as lichen planus (Figure 10-7)

• Vulvar diseases including vulvar intraepithelial neoplasia (VIN) (Figure 10-8).

FIGURE 10-5 Bullous pemphigoid on the back of a 57-year-old man with many intact bullae. A 4-mm punch biopsy was performed on the edge of an intact bulla and the diagnosis was confirmed.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-6 A 4-mm punch biopsy of the scalp is performed in this young woman with scarring alopecia. Subcutaneous fat is visible at the base of the biopsy. The patient was determined to have lichen planopilaris.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-7 Lichen planus with a lacy white pattern on the buccal mucosa. The presence of Wickham’s striae bilaterally in the mouth makes lichen planus likely. To establish a diagnosis histologically, a 4-mm punch biopsy of the buccal mucosa can be performed. Hemostasis can be achieved with aluminum chloride or electrocoagulation. A suture is rarely needed and is generally more uncomfortable for the patient.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-8 A 59-year-old woman with a long history of condyloma acuminata has suspicious areas of leukoplakia of the vulva. This photograph shows the vulva after two punch biopsies were performed. Both areas were found to have vulvar intraepithelial neoplasia 2 (VIN 2).

(Copyright Richard P. Usatine, MD.)

The following types of conditions may be diagnosed with a shave biopsy, but a punch biopsy can be an acceptable alternative:

• All types of nonmelanoma skin cancers and precancers (Figure 10-9)

• All benign skin neoplasms.

FIGURE 10-9 Nodular BCC on the back. A punch biopsy was used to establish the diagnosis. However, a shave biopsy would have been adequate and less invasive.

(Copyright Richard P. Usatine, MD.)

Punch biopsy can be used to remove any small skin lesion. The following lesions are often removed using this technique:

• Small nevi

• Small dermatofibromas.

A punch instrument can be used to create an opening in an epidermal inclusion cyst for a minimally invasive cyst removal. Some clinicians use a punch incision to remove small lipomas (see Chapter 12, Cysts and Lipomas).

Relative Contraindications and Cautions

Punch biopsy is a more invasive biopsy technique than needed for most BCCs or SCCs, which can be diagnosed by shave biopsy. In one study there was no significant difference in the accuracy rate for histologic classification of BCCs with both the shave and the punch biopsy.¹ Punch biopsies generally bleed more than shave biopsies and the risk of infection is somewhat higher than for a shave biopsy.

A punch biopsy does have certain risks that are greater than those of a shave biopsy, including the possibility of cutting larger blood vessels and nerves. Therefore, clinicians must be familiar with the underlying anatomy. Fortunately, most major nerves and blood vessels are deeper than a punch instrument, but digital nerves and the temporal branch of the facial nerve are more superficial and care needs to be taken in these areas (Figure 11-2 of Chapter 11). Punch biopsies over the digits or the eyelid margins are generally to be avoided. When possible, it is also prudent to avoid doing a punch biopsy over superficial arteries such as digital or temporal arteries. Caution should also be exercised over areas where there is little soft tissue between the skin and the bone (over the tibia, digits, and ulna) because the punch can cut through the underlying bone.

Making A Diagnosis

It helps to have a good idea of the differential diagnosis before choosing the biopsy type and location. For most punch biopsies, a clinician should choose a punch size that will result in excision of the whole lesion or will provide a sample of the portion of the lesion that appears to have the worst pathology. However, for bullous disorders such as pemphigus or pemphigoid, it is best to punch the edge of the bulla to include the perilesional skin (Figure 10-10). A scoop shave under an intact bulla or at the border of a bulla may yield an equally good specimen. The goal is to keep the epidermis attached to the dermis at the edge of the bulla.

FIGURE 10-10 Bullous lichen planus on the back. A punch biopsy should include a whole intact bulla or the edge of a bulla.

(Copyright Richard P. Usatine, MD.)

When performing a biopsy on an ulcerative lesion of unknown origin, it is helpful to remove tissue from the edge of the ulcer rather than the center portion. For example, if pyoderma gangrenosum is suspected, the biopsy should include the edge of the lesion, with some perilesional skin (Figure 10-11).

FIGURE 10-11 Pyoderma gangrenosum on the leg, with diagnosis confirmed by punch biopsy of an active edge.

(Copyright Richard P. Usatine, MD.)

Additionally, before starting the biopsy the clinician should also have in mind whether the specimen will be sent for standard formalin-fixed hematoxylin and eosin (H&E) stain, direct immunofluorescence (DIF), or culture. For example, to diagnose bullous disorders, the specimen may be sent for both H&E and DIF. The biopsy for immunofluorescence is performed on perilesional skin not including the lesion itself. Suspected conditions for which a biopsy may be needed for DIF include the following:

• Discoid lupus erythematosus and SLE (Figure 10-1)

• Pemphigus (Figure 10-12)

• Bullous pemphigoid (Figure 10-5)

• Lichen planus (Figure 10-13)

• Cicatricial alopecia (Figure 10-6)

• Epidermolysis bullosa acquisita (Figure 10-14).

FIGURE 10-12 Pemphigus foliaceous on the trunk. A 4-mm punch biopsy was performed on the edge of a bulla. If direct immunofluorescence is needed, a second 4-mm punch biopsy should be performed on perilesional skin of a relatively fresh lesion.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-13 Three variations of lichen planus (LP): (A) LP on the back of a black woman. (B) Hypertrophic LP on the leg. (C) Annular LP on the breast. All three diagnoses were made with 4-mm punch biopsies sent for standard pathology.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-14 Epidermolysis bullosa acquisita seen with blisters and erosions on the leg. Because there are many disorders that can do this, a 4-mm punch biopsy of a blister or the edge of a blister should be performed for a definitive diagnosis. Additional information can be obtained with a second 4-mm punch biopsy for direct immunofluorescence on perilesional skin.

(Copyright Richard P. Usatine, MD.)

Some of these conditions may be diagnosed with standard histology only and the biopsy for DIF may be a second step only if needed. DIF requires Michel’s media for transport and should not be put into standard formalin. Unfortunately, this medium needs refrigeration and has a short shelf-life so keeping it around the office is inconvenient. If two specimens are being sent simultaneously for DIF and standard pathology, two punch biopsies should be performed remembering that the DIF specimen is taken from perilesional skin.

If a fungal infection is suspected, periodic acid Schiff (PAS) stains are useful and can be done from the specimen in the formalin. If a culture is desired for a deep fungal infection such as sporotrichosis, the specimen can be sent on a sterile saline-soaked sterile gauze pad in a sterile urine container (Figure 10-15). This technique also works for suspected atypical mycobacterial infections (Figure 10-16).

FIGURE 10-15 Disseminated sporotrichosis. A 4-mm punch biopsy was sent for standard histology and a second 4-mm punch was sent on sterile saline for fungal culture.

(Courtesy of Eric Kraus, MD.)

FIGURE 10-16 Mycobacterium abscessus infection on the leg diagnosed with a 4-mm punch biopsy sent for AFB stain and culture.

(Copyright Richard P. Usatine, MD.)

Equipment

The following equipment is used to perform a punch biopsy (Figure 10-17):

FIGURE 10-17 Punch biopsy instrument set. The needle holder and extra Adson forceps with teeth are useful when the punch defect is sutured.

(Copyright Richard P. Usatine, MD.)

• Punches (also called trephines) (2 to 10 mm are available; 3 to 6 mm are preferred)

• Iris scissors (curved or straight)

• Adson forceps without teeth for lifting the specimen gently

• Needle holder and sutures or hemostatic solution

• Adson forceps with teeth for suturing (optional).

Punches come in various sizes ranging from 2 to 10 mm and are available as reusable steel punches and disposable punches (Figure 10-18). Disposable punches have the advantage of being presterilized and there is no concern about them losing their sharp edge. Reusable punches are more expensive, require sterilization between procedures, and must be maintained by proper, skilled sharpening. We use disposable punches for quality and convenience.

FIGURE 10-18 Punch biopsy instruments with visible window to improve the procedure (VisiPunch). Huot instruments makes these sharp and effective tools from 2 to 10 mm in diameter.

(Copyright Richard P. Usatine, MD.)

The Huot VisiPunch has the wonderful advantage of allowing the clinician to see through the punch instrument while performing the procedure. This allows one to place the punch on the skin and make sure the whole lesion is within the punch before starting the cut. Also, one can see the depth better and have a better idea of when the punch core releases from the dermis below. (Fusiform punches are available and are described in Chapter 11, The Elliptical Excision).

Choosing the Punch Size

A 4-mm punch is usually adequate to obtain sufficient tissue for pathology. When the lesion is smaller than 6 mm, the punch size can be determined by the diameter required to completely excise the tissue. Punch biopsies done with 10-mm punches may produce standing cones (“dog ears”) when closure is attempted (see Chapter 12). If the lesion requires a punch of larger than 6 mm, it is best to do an elliptical excision (see Chapter 11). Punch biopsies between 3 and 6 mm should obtain adequate tissue and be easy to close with a good cosmetic result. A minimum of a 4-mm punch is generally preferred by the dermatopathologist to provide adequate tissue for diagnosis.

Choosing Whether to Suture the Punch Defect

• Punch defects 2 or 3 mm in size can be left to heal by secondary intention.

• Punch defects of 4 mm in one study healed as well by secondary intention compared with suturing with one interrupted 4-0 nylon suture.² Blinded observers saw relatively little difference in the 4-mm punch results at 9 months. Note that no electrosurgery, aluminum chloride, or other hemostatic agents were applied to the biopsy sites, only Gelfoam was used for hemostasis in the nonsutured wounds. All wounds were dressed with petrolatum under gauze covered by an occlusive transparent dressing (Tegaderm). Dressings were left in place for 3 days, after which the Gelfoam was removed from the second-intention site and both biopsy sites were cleansed with water to remove any exudate. Tegaderm was reapplied at that visit and then weekly by the patient until the biopsy sites were completely healed or reepithelialized. Although these results are encouraging for the choice to leave 4-mm or less punch defects open to heal naturally, the use of Gelfoam and Tegaderm, both expensive materials, is not representative of standard punch aftercare. Also, this study required an additional visit 3 days postop. Also at 2 weeks, pain was reported more commonly for the site treated by second-intention healing and the pain lasted longer for the second-intention sites than for the primary closure sites.² Not surprisingly, unblinded patients preferred suture closer of the 8-mm punch biopsy sites.² With this data, I personally inform the patient of the risks and benefits of suturing and make a joint decision keeping many factors in mind.

• If a biopsy is being performed on an inflammatory lesion in which there may be a secondary bacterial infectious component, it is better not to suture the wound, but rather to allow it to heal by secondary intention. Although the worsening or creation of an infection in a punch biopsy is extremely rare, it is even more rare to see an infection if the site has been left open.

Punch Biopsy: Steps and Principles

Critical steps in a punch biopsy procedure include the following:

• Using 1% lidocaine with epinephrine for anesthesia and hemostasis.

• Cutting the punch biopsy down to the correct depth (into subcutaneous fat)

• Not crushing the tissue while handling the specimen.

• Stopping the bleeding adequately

• Avoiding dog ears in the final repair.

Preoperative Measures

• Determine the size punch needed and consider the pros and cons for suturing the defect if the punch size is 4 mm or less.

• Discuss with the patient the biopsy options and pros and cons for suturing the defect if the punch size is 4 mm or less. Obtain informed consent in writing. (See Appendix A for a sample informed consent form titled Disclosure and Consent: Medical and Surgical Procedures.)

• If sutures are to be used, choose the type of suture and set up the sterile supplies and equipment for the procedure.

• If the punch site will become less visible after anesthesia is applied, it helps to mark the area to be punched with a surgical marker. It need not be a sterile marker if the skin is prepped after marking. If the punch will be taken from a large involved area, the marking helps to make sure that the anesthesia and cut are in the same area.

• Lightly prep the area with alcohol or another antiseptic.

• Inject local anesthesia. Use a 27- or 30-gauge needle with 1% lidocaine and epinephrine (buffer the lidocaine for less pain; see Chapter 3). 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. It is important to infiltrate the skin surface and the dermis to the full depth of the planned punch (Figure 10-19B). Wait 10 minutes for maximum vasoconstriction and hemostasis. This is a good time to complete your pathology consult.

FIGURE 10-19 Punch Sequence

(A) A 62-year-old woman presented with a dark spot on her back for 6 months. (B) Local anesthesia with 1% lidocaine and epinephrine was injected using a 30-gauge needle. The anesthesia is injected more deeply at first and then more superficially to make sure the punch biopsy site is completely anesthetized. (C) After sterilely prepping and draping the site, a 4-mm VisiPunch is placed on top of the lesion to make sure that it will provide an adequate biopsy. The lesion can be seen within the punch. (D) The skin is stretched perpendicular to skin lines and the punch biopsy instrument is twirled clockwise and counterclockwise until the blade cuts down to the subcutaneous fat. Once the fat layer is reached, the punch is lifted. (E) The biopsy specimen is gently lifted so that it may be snipped off with a curved sharp iris scissor. Any sharp, pointed small tissue scissor would also work. (F) The specimen is pulled to the side to make room for the scissor to snip the base. (G) The punch specimen is removed. (H) The punch defect is sewed. The tip of the needle is viewed in the hole before the stitch is completed. (I) One interrupted suture is sufficient for closure of this punch biopsy.

(Copyright Richard P. Usatine, MD.)

Cutting the Punch Biopsy

• Prep the area with iodine (Betadine) or chlorhexidine (Hibiclens).

• If sutures are to be placed, clean your hands and apply sterile gloves and use a sterile fenestrated drape.

• Avoiding dog ears can be done by stretching the skin perpendicular to skin lines before and during the punch (Figure 10-19D). This tension should be maintained throughout the punch procedure until the dermis is fully breached. This stretching perpendicular to relaxed skin tension lines will allow the resultant wound, circular under tension, to revert to an oval or fusiform shape when the retention is relaxed. The oval defect will be aligned with the relaxed skin tension line to facilitate closure and optimize cosmesis. This is more important with punch biopsies over 5 mm in diameter.

• In Figure 10-19A, a pigmented lesion is being biopsied with a 4-mm punch. The punch is held above the area and is brought down over the specimen so that the specimen is centered under the punch (Figure 10-19C).

• The punch is then held between the thumb and forefinger of the dominant hand.

• With downward pressure, the punch instrument is rapidly rotated back and forth between the fingers until it penetrates completely through the dermis. Feel for a sensation of getting through a firm substance and moving into the less firm subcutaneous (SQ) fat. Pull up the punch and look for signs that the depth is correct. The punch specimen often raises above the surrounding tissue when the tissue has been cut to the fat layer (the dermis holds it in place if the depth is not correct). The bleeding is often increased when the cut reaches the SQ fat, and if you pull up on the specimen you may see the yellow fat color below. If the cut was not deep enough, reinsert the punch and continue cutting until the depth is correct.

• The punch instrument is then removed, and the specimen remains in the center of the site. Rarely the specimen may shear off and pull away with the punch. If this happens, it can be removed from the punch with a needle. One advantage of the VisiPunch is that the punch specimen never gets stuck in the metal tube of a sealed punch.

• If the specimen is not elevated, apply downward compression of the area around the specimen for elevation. The specimen can then be further elevated gently with a forceps (being careful not to crush the specimen) (Figure 10-19E) and cut from its base with a sharp iris scissor (Figure 10-19F). Variations on this method include putting a skin hook or small needle into one side of the specimen and elevating it.

• It is important to remember that every effort needs to be made to handle the specimen lightly and to resist the tendency to compress or crush the specimen with the teeth of the forceps. Crushed samples may result in distortion of nuclei or cell architecture.³

• Be prepared to handle bleeding that may drip down the skin by placing a gauze under the punch site in the direction that gravity will take the blood from the punch site.

Stretching the Skin to Prevent Standing Cones

Stretching the skin to prevent standing cones (“dog ears”) is especially important when doing a punch larger than 5 mm or performing a punch on the face or other cosmetically important area. Figure 10-20 shows how stretching the skin perpendicular to skin lines will allow for a better cosmetic outcome.

FIGURE 10-20 (A) Stretching the skin during a punch biopsy: 1, Skin stretched perpendicular to skin lines. 2, Punch to subcutaneous fat. 3, Oval defect is formed. 4, Closed defect is now linear. (B) Oval defect seen in a punch biopsy within a rash that was created by stretching the skin during the punch procedure.

(Copyright Richard P. Usatine, MD.)

Hemostasis and Repair

• If no sutures are to be placed, hemostasis can be achieved with aluminum chloride on a cotton-tipped applicator (CTA). If this does not work, electrocoagulation is another option. If the aluminum chloride solution is aqueous, there are no concerns about using electrocoagulation immediately as needed. Electrocoagulation also will cause the defect to shrink in size.

• If electrocoagulation is not working, hold pressure on the wound and consider placing a suture.

• Preventing dog ears before suturing: If the defect is round because the initial stretching perpendicular to skin lines was not employed and dog ears seem to be likely, try gently undermining the defect with blunt dissection using the iris scissor. This often will allow the defect to elongate along skin lines. Another option has been described using two skin hooks. The skin hooks are placed on opposite ends of the wound following skin lines and the circular defect is stretched for 1 minute. This method was found to prevent dog ears in one study.⁴

• Many choices for suturing a punch biopsy are available. Nylon suture is a good and inexpensive material to use. Usually 4-0 or 5-0 nylon is adequate. Money can be saved by purchasing sutures with a short 9-inch monofilament meant to close punch biopsies.

• Vicryl (polyglactin 910) was compared with nylon for closure of punch biopsy sites in one study.⁵ Each 3-mm punch site was closed with one simple suture. The sites were evaluated at 2 weeks and 6 months for redness, infection, dehiscence, scar hypertrophy, and patient satisfaction. The authors found no statistically significant difference between the two suture materials in any of the above parameters.⁵

• Fast-absorbing gut can be used for closure if the area is not under tension and it is difficult for the patient to return for suture removal.

• One to two interrupted sutures is adequate for a 3- or 4-mm punch and two to four sutures may be needed for 5- or 6-mm punch biopsies (Figures 10-21 and 10-22).

FIGURE 10-21 Punch biopsy defect closed with two interrupted 5-0 Prolene sutures after a 4-mm punch was used to excise a pyogenic granuloma on the face.

(Copyright Richard P. Usatine, MD.)

FIGURE 10-22 Punch biopsy was closed with 5-0 Prolene on the face of a young woman in which a changing pigmented lesion was excised with a 5-mm punch. To obtain a good cosmetic closure, three interrupted sutures were placed.

(Copyright Richard P. Usatine, MD.)

Dressing and Aftercare

• Cover the final wound with clean petrolatum and a sterile adhesive bandage.

• If the bleeding is hard to stop or if the area is very vascular, consider applying a small pressure bandage to avoid postop bleeding.

• Explain aftercare to the patient and/or family members. We usually suggest patients keep the area dry for 24 hours then they may bath normally. See Appendix A for a patient information handout titled Care of Your Skin after a Punch Biopsy.

• Sutures are generally left in place for 5 to 7 days on the face and 7 to 14 days elsewhere on the body. See Chapter 35 for further details of postoperative wound care.

Suggestion for Learning the Punch Biopsy Technique

When learning punch biopsy technique, it may be helpful to practice on an orange, banana, or pig’s foot. The twirling motion to cut a core biopsy can be practiced on just about any fruit or meat, but the stretching of the skin against skin lines is very hard to simulate.

Less than Optimal Outcomes

Complications that may arise from a punch biopsy include the following:

• Producing a divot or indentation that persists

• Cutting a vital nerve or artery (rare)

• Erythema that may last for months and often resolves

• Slow healing for a punch on the lower leg or one that is left open

• Hypopigmentation or hyperpigmentation that can be permanent

• Infection (Figure 10-23)

• Hypertrophic or keloidal scarring may rarely occur, particularly with patients predisposed to their occurrence

• Regrowth of an incompletely excised lesion (less common than with a shave biopsy).

• Standing cones or dog ears that do not flatten

FIGURE 10-23 An infected punch biopsy 1 week after a 6-mm punch was performed with no closure. Unfortunately, silver nitrate was used for hemostasis and this large lesion was left open to heal. Most clinicians would close a punch biopsy of this size and avoid silver nitrate.

(Copyright Richard P. Usatine, MD.)

Serious complications are extremely infrequent with punch biopsy.

Patients should be informed that a punch biopsy obtained on mobile areas such as the back, which is stretched each time we bend or breathe, or the arms, which are stretched each time the muscles are flexed or pumped, may well result in some stretching of the wound. The ultimate scar, while frequently flat and flesh colored, may become the size of the area that was removed via punch technique and not be a simple linear scar.

Specific Examples for Punch Biopsies

Erythroderma

It is important to establish the cause of erythroderma (Figure 10-24) quickly so that specific therapy can be initiated. A 4-mm punch biopsy is a good start. Call the pathologist to ask for a rush order because erythroderma can be a life-threatening condition.

FIGURE 10-24 A patient with erythroderma and small pustules visible on the posterior thigh. While pustular psoriasis was suspected, a 4-mm punch biopsy was performed of this area and sent to pathology with a rush order. The patient was hospitalized and the following day the diagnosis of pustular psoriasis was confirmed. Intensive treatment allowed the patient to leave the hospital improved in a few days.

(Copyright Richard P. Usatine, MD.)

Palmoplantar Psoriasis

The diagnosis of psoriasis can be made based on the clinical presentation in most cases by using clues such as the distribution, appearance, and chronicity of the lesions. A punch biopsy can be used to confirm the diagnosis in an atypical presentation when there is uncertainty. Sometimes it is difficult to determine whether hyperkeratosis on the palms and soles is from psoriasis or other conditions such as dyshidrotic eczema or dermatophytosis. A punch biopsy can help direct therapy (Figure 10-25). It is especially helpful to confirm a diagnosis of palmoplantar psoriasis because these patients often need potent systemic therapy with agents that are known to have serious potential risks. Perform the punch over an area of the hand that is affected but has soft tissue below it. A shave biopsy is another option.

FIGURE 10-25 Hyperkeratotic plaques with scale on the hands and feet. A 3-mm punch biopsy of the hand confirms the diagnosis of palmar plantar psoriasis.

(Copyright Richard P. Usatine, MD.)

Morphea

Flat atrophic shiny or wrinkled patches on the skin can be morphea (localized scleroderma) or lichen sclerosis. It is difficult to tell just by looking so a punch biopsy is very helpful. Figure 10-26A shows a 4-mm punch site from morphea on the abdomen of a young woman. In Figure 10-26B, morphea is seen on the breast of a 30-year-old woman. Diagnosis was confirmed with a 4-mm punch.

FIGURE 10-26 (A) Morphea or localized scleroderma on the abdomen of a young woman. Diagnosis confirmed with a 4-mm punch. (B) Morphea on the breast of a 30-year-old woman.

(Copyright Richard P. Usatine, MD.)

Trichotillomania versus Other Types of Alopecia

The cause of hair loss is not always obvious by history and physical exam. In Figure 10-27, a 37-year-old woman was concerned about an area of alopecia on her scalp. She admitted that her scalp was pruritic and that she was under much stress. Trichotillomania was suspected due to the story and broken hairs, but the patient did not initially admit to pulling her hairs. A 4-mm punch biopsy confirmed the suspected diagnosis. Note that the biopsy site was not closed and hemostasis was obtained with electrocoagulation. When the histology supported trichotillomania, the patient took responsibility for her behavior and was able to stop the hair pulling and excoriations.

FIGURE 10-27 A 37-year-old woman with an area of alopecia on her scalp. She admitted that her scalp was pruritic and that she was under much stress. Trichotillomania was suspected due to the story and broken hairs, but the patient did not initially admit to pulling her hair. A 4-mm punch biopsy confirmed the suspected diagnosis. Note that the biopsy site was not closed and hemostasis was obtained with electrocoagulation.

(Copyright Richard P. Usatine, MD.)

Pemphigus

A man presented with blisters on his arms. A 4-mm punch biopsy of the edge of a bulla led to the diagnosis of pemphigus vulgaris (Figure 10-28). A second 4-mm punch biopsy of perilesional skin was also sent for direct immunofluorescence in Michel’s media. The result confirmed the diagnosis.

FIGURE 10-28 A man presented with blisters on his arms. A 4-mm punch biopsy of the edge of a bulla led to the diagnosis of pemphigus vulgaris.

(Courtesy of Jennifer Welsh, MD.)

Coding and Billing Pearls

The punch procedure is either used as a form of biopsy and billed under the biopsy codes or used to fully excise a lesion and then billed under excision codes. Occasionally it can be confusing sometimes to decide whether the punch procedure is a “biopsy” or “excision.” Clear-cut examples of punch biopsies include sampling a possible skin cancer or removing a piece of skin to determine the cause of an unknown rash. Excision codes are used for those punch procedures that are used to remove a small benign nevus or another small benign lesion. The intent is to excise the whole lesion, and even though it is recommended to send all pigmented lesions for confirmatory pathologic diagnosis, the primary reason for the procedure was not a “biopsy” but a removal of the lesion itself. Malignant excision codes are generally not used with the punch procedure because punch instruments are small and not likely to provide for adequate margins around skin cancers for the definitive procedure.

Make sure that all documentation is consistent with the procedure that is billed. If the punch is done as a biopsy, call it a punch biopsy, but if the punch is done as an excision, call it a punch excision or just an excision.

Punch biopsy CPT codes and fees are summarized in Table 38-7 of Chapter 38, Surviving Financially. Note that, although these codes cover punch biopsies they also cover biopsies done by shave 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. The codes are also independent of whether or not a suture was placed to close the punch.

CPT codes and fees for punch excisions are the same as for small benign excisions and are provided in Table 11-2 of Chapter 11. These codes are based on size and location so it is crucial to measure the lesion before excising it. If the lesion is cutaneous and will be fully removed, then the punch size is the lesion size for billing. If the lesion is subcutaneous, such as a lipoma or deep cyst, then the lesion size is the actual measured size before surgery and not the punch size. 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 an excision of a 1.1-cm lesion than a 1.0-cm lesion). The codes are also independent of whether or not a suture was placed to close the punch, but in many cases one or more sutures will be used because punch excisions tend to be larger than biopsies only.