Biopsy Techniques and Basic Excitions (Chapter 146)

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The cornerstone of dermatologic diagnosis is the correlation of clinical and histologic findings. A biopsy procedure is required in order to obtain tissue for pathologic examination, and fortunately the skin is more accessible than most other tissues. Modern instruments and techniques allow cutaneous biopsies to be performed efficiently with minimal tissue distortion. In some situations, a biopsy procedure is also curative, either coincidentally or intentionally. Knowledge of basic excisional surgical techniques can minimize cosmetic and functional impairment. Performance of a timely skin biopsy may also circumvent the need for more invasive procedures. Even critically ill patients can undergo a skin biopsy with minimal risk.
Site Selection
Performance of a biopsy that will yield accurate and relevant histologic information depends upon the selection of an appropriate lesion or site within a lesion (Table 146.1).
The anticipated depth of the lesion to be biopsied must also be considered. In the case of a superficial lesion, e.g. an actinic keratosis versus Bowen disease, it can be assessed via a more "superficial" biopsy that extends to the papillary dermis. On the other hand, accurate diagnosis of a subcutaneous nodule, e.g. panniculitis versus polyarteritis nodosa, requires a biopsy that includes subcutaneous tissue.
Occasionally, fascia must be obtained, e.g. morphea profunda versus eosinophilic fasciitis. Disorders that primarily affect the collagen and elastic fibers within the dermis may have subtle histologic findings (e.g. atrophoderma of Pasini and Pierini) and longitudinally sectioned wedge biopsies that include both the affected area as well as adjacent normal-appearing skin prove most helpful.
Biopsy Technique Selection
Seven major methods are employed to biopsy skin: curettage, snip or scissors biopsy, shave biopsy, saucerization biopsy, punch biopsy, incisional biopsy, and excision in toto (Table 146.2). Depending upon the type of lesion and its size, several of these procedures are also curative, especially excision in toto. However, these methods do differ with regard to the quality and quantity of skin obtained. Lesional characteristics and operator experience are factors that influence the choice of a particular procedure.
Curettage is frequently used to remove clinically benign epidermal lesions such as verrucae or seborrheic keratoses, actinic keratoses (AKs), and basal cell carcinomas (BCCs), especially the superficial type. The curettings can also be used to confirm the clinical diagnosis, but histologic interpretation may prove more challenging if the tissue specimen is fragmented and its orientation becomes problematic. Snip or scissors biopsy is an efficient technique for assessing pedunculated lesions as well as removing benign growths (e.g. acrochordons, filiform warts).
The shave biopsy usually provides a specimen consisting of epidermis, papillary dermis, and sometimes reticular dermis (particularly in elevated lesions). It is a popular biopsy technique for recontouring papular, clinically benign lesions (e.g. irritated or unwanted compound and dermal melanocytic nevi, fibrous papules of the nose) where histologic confirmation is desired. Shave biopsy is also a useful procedure for diagnosing superficial carcinomas, e.g. nodular and superficial BCCs, squamous cell carcinoma (SCC) in situ, and lentigo maligna.
Some authors distinguish a shave biopsy from a saucerization procedure in which the depth of the biopsy specimen is intentionally deeper due to angulation of the blade. This latter technique is often used to biopsy melanocytic nevi with atypical features when the differential diagnosis includes a thin melanoma1. Its advantage is that it allows histologic examination of the entire lesion, which increases diagnostic accuracy, especially in the case of larger lesions (as compared to partial punch biopsy). Saucerization is also performed to confirm the clinical diagnosis of minimally invasive SCC or keratoacanthoma and to distinguish the former from a hypertrophic AK. The punch biopsy supplies a cylindrical to conically shaped specimen consisting of epidermis, dermis and, sometimes, subcutaneous fat. The volume of tissue sampled correlates with the size of the punch biopsy instrument. In general, the diameter of the metal "barrel" varies from 2 to 6 mm, and the wider the diameter, the greater the likelihood of obtaining subcutaneous fat. However, the thickness of the dermis and the amount of subcutaneous fat required to establish the diagnosis must be kept in mind. Punch biopsies are particularly helpful for examining processes within the dermis, e.g. tumors, inflammation (see Table 146.2). In the case of tumors, sampling a majority of the lesion is desirable, so that for large-sized tumors, multiple punch biopsies may be required.
The incisional biopsy removes a wedge of tissue from the center or edge of a lesion (see Site selection) and is the best option for obtaining deep subcutaneous fat or fascia for histologic examination. It is also used to sample a significant portion of large-sized tumors. Excision in toto removes the entire lesion and includes epidermis, dermis and subcutaneous fat. For these reasons, it is often utilized when the leading clinical diagnosis is invasive cutaneous melanoma.
Specimen Handling
Transportation of the biopsy specimen to the laboratory differs according to the processing and type of examination required. Most specimens are placed in formalin, but, occasionally, special carrier media are necessary (Table 146.3). Fresh tissue specimens are sent on saline-moistened gauze and either promptly delivered to the laboratory or packed in ice; the laboratory must be in reasonable proximity and have the capability of processing the tissue immediately. When handling small or thin biopsy specimens, it is important to confirm that they are clearly within the formalin solution and not adhering to the upper portions of the container or lid; this prevents desiccation artifact.
A protocol must be established within the clinician's practice to ensure that specimens and results are appropriately tracked and assigned to the correct patient. Immediately after the biopsy specimen has been obtained, it should be placed in a container prelabeled with the patient's name and other identifying information. If multiple biopsies are to be performed, pre-labeling the containers alphabetically and with the respective sites avoids confusion. A specimen log book (Table 146.4) ensures notification of the results to the patient and disposition of recommended care.

Patient Preparation
A discussion of the reason(s) to do the biopsy, the site to be biopsied, and the technique to be used can be brief and to the point. Informed consent requires a discussion of the major risks, which include bleeding, discomfort, infection, and scarring (see Ch. 151). Bleeding can usually be controlled by firm pressure at the site of the wound, but may require more aggressive forms of hemostasis. Discomfort is usually minimal, although some sites such as the forehead, fingers and feet may throb. Infection is unusual. Except when the area to be biopsied is already infected or the site is mucosal, the skin can be prepared by application of an antiseptic agent and the procedure is then considered to be a clean procedure. For clean procedures of non-mucosal, non-infected sites, preoperative prophylactic antibiotics are currently not recommended, even in patients with artificial valves or joints (with the possible exception of sites at high risk of infection, e.g. groin, during the first 2 years after joint placement)2-4. The overall goal is a reduction in the emergence of antibiotic-resistant bacteria and in one study, for example, preoperative prophylactic antibiotics increased nasal carriage of methicillin-resistant Staphylococcus aureus5. Tables 151.2 and 151.3 review the guidelines for antibiotic prophylaxis as well as regimens for both oral and non-oral sites. Preoperative antibiotics are administered within a 2-hour window before the incision; there is debate as to whether or not a second dose is administered 6 hours later and under which circumstances antibiotics should be continued for 48-72 hours6. When pretreated with a 5-day regimen of intranasal mupirocin ointment (twice daily) and a total body wash with chlorhexidine soap (daily avoiding the eyes and ears), nasal carriers of S. aureus were observed to have fewer postoperative infections7.
Most patients are primarily interested in discussing whether or not there will be visible scarring. This is best predicted by the type of biopsy to be performed and the anatomic site. Generally, patients can be reassured that small biopsies may be done without grossly noticeable permanent "marks".
Many patients are anxious about the needle sticks required for administration of the local anesthesia and the pain of the procedure. The patient's cooperation is easily obtained in an organized and peaceful environment with a calm and reassuring staff. A well-informed, comfortable patient in a supine position will tolerate the procedure without difficulty.
Site Preparation and Anesthesia
Effective site preparation is most efficient if a standard clinical protocol has been established (Table 146.5). Marking and photographing the site8,9, cleansing the skin (Table 146.6)10, and draping are important procedures prior to the instillation of local anesthesia. Local anesthesia is adequate for all skin biopsies and is reviewed in detail in Chapter 143.
When the local anesthetic agent is instilled into a deep compartment (i.e. subcutaneous fat; Fig. 146.1A), 5 to 10 minutes is required for anesthesia to develop on the surface of the skin. Gentle massage of the site may assist in spreading the agent subepidermally and achieving good anesthesia. Injection of the agent superficially, creating an edematous wheal, has immediate efficacy but is more painful (Fig. 146.1B). Since a punch or shave biopsy requires very little agent and therefore a very short injection time, superficial instillation is the technique often used. In addition, a wheal is helpful prior to a shave biopsy as the lesion is further elevated from the plane of the surrounding skin. Of note, since epinephrine (adrenaline) requires up to 15 minutes to produce maximal vasoconstriction and thereby minimize bleeding11, lidocaine without epinephrine is sufficient for an immediate biopsy. Regardless of other considerations, it is critical to have the local anesthesia in the compartment that is to be biopsied, i.e. a superficial wheal may be entirely adequate as anesthesia for a shave biopsy but will not suffice for an incisional wedge biopsy that extends into the subcutaneous fat.

All biopsy procedures require attention to hemostasis of the wound bed (Table 146.7; see Table 151.5). While styptics and absorbable hemostatic sponges are used for those wounds healing by second intention, punch biopsy sites are usually closed primarily with the suturing itself providing sufficient hemostasis. Wounds created during an incisional biopsy or excision in toto may require electrocoagulation for hemostasis before closure (see Ch. 140). The endpoint is no active bleeding in the wound bed. Bleeding within the dermis in the sides of the wound can
Urgery be controlled by suturing and does not need cautery. At times, to produce hemostasis, a large actively bleeding vessel may need to be identified, grasped with a hemostat, and tied off with an absorbable suture and a figure-of-eight stitch (Fig. 146.2).
Wound Closure
Closure of wounds created by a biopsy procedure may occur by either secondary or primary intention healing. Second intention healing repairs wounds by the processes of granulation tissue formation, epidermal cell migration, and contraction (see Ch. 141). These processes occur simultaneously, beginning within the first few days after surgery and continuing until the wound has completely re-epithelialized. For the remainder of the patient's life, maturation of the scar occurs, with gradual improvement in color, texture and contour. Indications, disadvantages, and contraindications for second intention healing are outlined in Table 146.8.
Closure of the wound via suturing is regarded as primary intention healing. The same processes of granulation tissue formation, epithelial migration, and contraction occur; however, they are significantly reduced, because the sides of the wound are already apposed. Processes related to fibroblast activity and collagen deposition play a more important role in primary intention healing, allowing adequate tensile strength to develop in order to keep the wound closed12. These scars also undergo maturation throughout the remainder of the patient's life. Both secondary and primary intention healing are promoted by appropriate wound care and dressings.
For primary intention healing, wounds may be closed either by placement of a simple full-thickness suture or by layered closure. In a layered closure, subepidermal buried sutures appose subcutaneous and dermal tissue, provide alignment of the wound edges, set up the wound edges for eversion, and assist with hemostasis by occluding any vessels bleeding within the edge of the wound. In addition, the subepidermal sutures supply strength to handle tension within the closure. Although subepidermal sutures are generally absorbable, they remain intact within the tissue for 8 to 12 weeks, the period during which the scar is slowly acquiring tensile strength. As a result, they prevent dehiscence and spread of the scar. Epidermal or skin sutures appose the epidermal edges and complete eversion. They can also correct minor degrees of misalignment in the closure. Satisfying these objectives via conscious placement of sutures improves the function and appearance of the scar13,14.
Knotting is the means for stabilizing the placement of the suture, usually produced with an instrument tie (Fig. 146.3). The first throw of the knot is started by pulling the long end of the suture tight with the fingers of the non-dominant hand and looping it around the needle holder once or twice. The needle holder then grasps the short end and pulls it through the loops. The loops are pulled across the wound so that they lie flat. These steps are then repeated to produce the second throw of the knot, but this time with the loop in the opposite direction around the needle holder. When this second loop is pulled across the wound, a square knot is created. Depending on the memory and thickness of the suture material (see Ch. 144), three to six throws may be required to properly secure the knot. Care is taken to ensure that the knot lies flat without significant tension or tightness15. Sometimes, a loose loop is left in the second throw, to allow the suture to adjust to any wound swelling that may develop.
Sutures commonly used for subepidermal placement are composed of synthetic absorbable materials, e.g. braided polyglactin (Vicryl®), monofilament polydioxanone (PDS®). The interrupted buried dermal stitch (Fig. 146.4A) is designed such that the stitch is in the dermis and fat and the knot is inverted (buried). The needle enters the undermined deep surface of the wound (not the sidewall) and passes up into the dermis. After crossing the wound, it enters the opposite side of the wound at the same level in the dermis and then exits the deep surface. The knot is then tied and the ends of the suture cut. When the suture material is released, the knot settles within the deep portion of the wound, minimizing tissue reaction to the suture and extrusion through the wound. Enough buried dermal sutures are placed such that tension is eliminated and the deep tissues are completely apposed. In order to facilitate eversion, this basic stitch may be modified, creating a buried vertical mattress stitch16. In this stitch, the suture is nearest to the skin surface (within the superficial dermis) at a point 3-4 mm lateral to the wound edge, and then it exits the wound deeper in the dermis (Fig. 146.4B). A very subtle dimple may be appreciated above the suture where it lies superficially in the dermis. On occasion, a running dermal stitch is used to close the deep component. This stitch is begun similarly to the interrupted buried dermal stitch, but, after tying, only the short end of the suture is cut. The needle then draws the suture through the subcutaneous fat and dermis on one side, passing to the other side, and then continuing along the length of the wound. At each step, the suture is pulled tightly to appose the edges. At the end of the wound, the knot is achieved by tying the loose end to the last loop. This stitch is only used when there is little tension in the wound, as rupture of the suture material anywhere along the suture line would release the suture for the entire length of the wound, allowing dehiscence or spread of the scar.
Monofilament nylon (Ethilon®) or polypropylene (Prolene®) are commonly used epidermal sutures. The simple interrupted epidermal stitch is placed by passing the needle through the epidermis into the superficial dermis in a plane just superior to the buried suture, across the wound, into the dermis on the opposite side and then up through the epidermis (Fig. 146.4C). Eversion is assisted by placing the suture closer to the wound edge but relatively deeper in the wound so that the epidermal surface does not roll. Using the curve of the needle to create the path for the suture also facilitates eversion. If there are no buried sutures, the stitch apposes the edges for the full depth of the wound (e.g. for closure of punch biopsies).
The vertical mattress stitch (Fig. 146.4D) is sometimes used for wounds in thicker skin where eversion may be difficult and when a single suture apposing the deep and superficial edges is desired. This stitch has four points of entry into the skin. It is started by passing the needle through the epidermis 5-8 mm lateral to the wound edge, exiting from the deep portion of the wound. It re-enters the opposite side of the wound in the same deep position, and exits from the epidermis equidistant from the wound edge as the entry point. The needle is reversed and the epidermis is re-entered closer to the wound edge; it is then drawn through the upper dermis before crossing the wound, entering the dermis and finally exiting close to the wound edge. Once tied, the knot is positioned on one side of the wound, not over the line of closure.
A horizontal mattress stitch can be used in thinner skin such as the neck or the dorsum of the hand, and it also has four points of entry into the skin. The first two points of entry are the same as in the vertical mattress stitch (Fig. 146.4E), but closer to the wound edge (i.e. 3-5 mm). However, after the needle is reversed, the third point of entry into the epidermis is 3-4 mm from the exit point, on the same side of the wound edge and equidistant from the wound edge. The suture is then drawn through the deep portion of the wound again, crosses the wound, enters the opposite sidewall in the same deep position and finally exits at the same distance from the wound edge, 3-4 mm from the first entry point. This knot, when tied, is also positioned on one side of the wound, not over the line of closure.
Since sutures of both the vertical mattress and horizontal mattress stitches must be removed within 1-2 weeks (depending upon the site), they are not good stitches to use as the sole means of closure in a wound with tension. Of note, a variant, the running combined simple and vertical mattress stitch, also everts well and saves surgical time17.
In the presence of buried sutures, a simple running epidermal stitch may be placed for opposition of the epidermal edges. This running stitch may be passed via the dermis and the epidermis in a fashion similar to the simple interrupted epidermal stitch (Fig. 146.4F). In addition, the needle may be passed under the superficial loop of the previous stitch, thus creating the running locked stitch (Fig. 146.4G). This stitch can assist with hemostasis and will not completely unravel if the suture breaks under wound tension. Alternatively, the stitch may be placed within the upper dermis, referred to as a running subcuticular stitch (Fig. 146.4H). This stitch is placed with the needle passing in and out of the upper dermis in a plane horizontal to the surface. Two knots are tied, one on each end of the wound, and they are the only visible portion of the suture. Running stitches are frequently used to save time, but they can accentuate minor misalignments of the wound edges18. They also do not necessarily prevent track marks, which occur because of tension, inadequate undermining, ineffective buried dermal sutures, and poor placement of the epidermal sutures.
Non-absorbable sutures that pass through to the surface of the skin are removed. If they remain in place, they cause tissue inflammation and create a less than optimal functional and cosmetic result. To remove a suture, the thread is severed near the knot with either fine-tipped scissors or a #11 blade. The knot is then pulled over the line of closure so that the wound edges are not pulled apart. Sutures on the face are generally removed after 5-7 days, and sutures elsewhere, at 10-14 days. If buried dermal sutures are used, the epidermal sutures may be removed at the earlier times. Sometimes, absorbable suture material is used for superficial closures, especially in the simple running epidermal stitch, precluding the need for suture removal. Sterile adhesive tapes such as Steri-Strips™ or tissue glue (Dermabond®) are also occasionally used instead of epidermal sutures to avoid the need for suture removal, but they are ineffective in producing eversion and in dealing with tension. When compared to traditional epidermal sutures, adhesive tapes in one study produced an equivalent result in overall scar cosmesis, if subcutaneous closure had been achieved with no tension and there was perfect alignment of the surface19. Of note, in another study, no differences in cosmetic outcome were observed when adhesive tapes plus dermal sutures were compared to dermal sutures alone20. The use of adhesive tapes after suture removal may, however, reduce the amount of scar spreading when they are left in position for several weeks21. Table 146.9 outlines alternatives to sutures for wound closure2
A biopsy is indicated at any time if the clinical diagnosis of a cutaneous disorder is unclear or must be substantiated before a course of treatment is undertaken. Inflammatory disorders are often biopsied to assist in the differentiation of multiple processes that may have a similar clinical appearance. Infectious processes are biopsied so as to detect the causative organism in tissue sections and/or to obtain tissue for culture. Lesions suspicious for malignancy are biopsied in order to develop a surgical plan appropriate for the tumor type. Biopsies of normal skin may also be performed, to obtain tissue for metabolic or genetic studies26,27. Skin biopsies may even be performed prenatally.
Most patients can safely undergo a skin biopsy, so contraindications are not absolute. A skin biopsy may save the patient from a more invasive procedure if the disease process can be determined via histologic examination of the skin. Patients who are immunosuppressed because of medications (e.g. prednisone, chemotherapy, tacrolimus) or underlying diseases (e.g. HIV infection, lymphoma, leukemia) often require biopsies because of the complicated interplay between the underlying disorders and the side effects of therapy (e.g. infections, drug reactions).
In addition, there are no cutaneous or mucosal sites where a biopsy is contraindicated. Diagnostically, it is more useful to biopsy a lesion from the hand or the face that provides accurate information than it is to biopsy a late-stage, nonspecific lesion on the arm. Biopsies can be done on the legs of patients with diabetes mellitus as well as the digits of patients with vascular compromise, although greater attention to postoperative care is often necessary. For patients with coagulation or platelet disorders (due to either underlying diseases or medications), it may be preferable to biopsy a site that can be compressed to produce hemostasis. For example, if an arm or leg were biopsied, postoperative bleeding can be controlled by pressure applied by an elastic circumferential bandage.
In certain anatomic sites, it may be necessary to exercise caution to avoid injuring a vital structure (see Chs 142 & 151). The temporal nerve lies in a superficial location, just beneath thin dermis and subcutaneous fat, midway between the eyebrow and the temporal hairline. The spinal accessory nerve also courses superficially at the posterior edge of the sternocleidomastoid muscle at a point one-third of the distance between the mastoid process and the inferior attachments of the muscle. Severing these nerves leads to motor dysfunction; thus, these sites are best biopsied in a superficial manner. The temporal and thyroid arteries are also relatively superficial. Cutting them leads to temporary difficulty with hemostasis but has no long-term adverse effect.
Some lesions require special consideration before performing a biopsy. A mass that is pulsatile may indicate large arterial vessel involvement, a situation requiring additional clinical evaluation prior to biopsy and special surgical arrangements in case of bleeding. A post-traumatic cephalic mass or cystic midline lesion may need preoperative radiologic examination to determine any possible connection to the intracranial or intraspinal space28. Excision of a benign lesion, e.g. epidermoid inclusion cyst, on the upper trunk or shoulders of a patient who tends to form keloids must be carefully discussed, weighing the possibility of keloid formation against how bothersome the lesion is. Hypertrophic scars, on the other hand, are common and resolve with time and/or pressure as well as corticosteroid injections, and need not interfere with the performance of a biopsy.
While there are no absolute contraindications to performing a biopsy, a clinician will want to be aware of certain features of a patient's medical and surgical history in order to formulate an adequate surgical plan and to predict the need to manage possible complications. Table 146.10 summarizes information pertinent to the issues previously discussed. In particular, patients who are taking medications or have underlying disorders that lead to abnormalities in coagulation or platelet function should be identified in advance. Almost all procedures can be done despite a patient receiving warfarin, heparin, clopidogrel, apixaban, rivaroxaban29, or aspirin if the site of the biopsy is planned carefully and the options for hemostasis are readily available. The bleeding time may also be affected by alcohol ingestion, oral vitamin E, and nonsteroidal anti-inflammatory drugs, in addition to a number of alternative therapies, including garlic, gingko, ginger, ginseng, feverfew, fish oil and green tea30 (see Table 133.3). While biopsies may be done safely during pregnancy31, the emotional turmoil surrounding a coincidental miscarriage or pregnancy mishap is great enough to defer elective procedures (e.g. shave biopsy of an unwanted intradermal nevus) to the postpartum period, whereas biopsies of atypical pigmented lesions in which the differential diagnosis includes melanoma are not deferred. As long as they can cooperate, biopsies and excisions can also be done safely in children under local anesthesia.
Local anesthesia is achieved by wheal formation (see Fig. 146.1). Depending upon the size and thickness of the lesion, a curette 3-5 mm in diameter is held like a pencil and drawn with pressure across the lesion (if epidermal) or through the lesion (e.g. presumed BCC). With one smooth movement and moderate pressure (as well as opposing traction by the non-dominant hand), an epidermal sheet or ball of tissue may be obtained (Fig. 146.5). In the case of incomplete removal, further fragments may be obtained by repeated curettage. This type of biopsy assumes that healing will be by second intention. Hemostasis may be obtained by a styptic, electrodesiccation, absorbable hemostatic sponge, or pressure. The resulting scar is usually minimal in the case of epidermal lesions or of no significant concern in the case of a BCC, since later definitive treatment will produce the final scar.

Snip or Scissors Biopsy
Pedunculated lesions can be biopsied via a snip or scissors biopsy (Fig. 146.6). Local anesthesia is obtained by wheal formation in the upper dermis just under the narrow attachment of the lesion to the skin surface. For tumors with a very narrow neck, this type of biopsy can be done quickly without anesthesia. Scissors, usually fine iris scissors or sharp Gradle scissors, are used to separate the lesion from its base at the level of the skin surface. A toothed forceps is often used to handle the tissue. Healing is by second intention, and a styptic, electrodesiccation, absorbable hemostatic sponge, or pressure may be required for hemostasis. Scarring produced by this type of biopsy procedure is a small, subtle, often hypopigmented macule.
Shave biopsyShave biopsy is the most commonly used technique for obtaining a skin specimen for histologic examination (Fig. 146.7). A local anesthetic is used to produce a wheal under the lesion so that it is elevated above the plane of the surrounding skin. A #15 blade on a blade handle is used (almost parallel to the skin surface) to cut the specimen from its bed. Alternatively, only the blade without the blade handle is used. Cutaneous surgeons generally hold the blade or the blade handle like a pencil, to facilitate control of small movements. It is helpful to begin on one edge by holding the blade vertically and incising only through the epidermis. The blade is then turned to a horizontal position and a smooth sawing motion is used to complete the removal of the specimen. A good specimen may also be obtained by a single-edged razor blade held in a semi-curved shape32. The goal is a shallow, saucer-shaped defect and a single piece of unfragmented tissue; edges should be smooth. Forceps may be used to hold the specimen while in situ in order to supply traction against the movement of the blade and then to remove the entire specimen and place it in the appropriate container. However, the tissue must be handled gently so that crush artifact does not confuse the microscopic appearance. Toothed, as opposed to smooth or ridged, forceps minimize crushing of the tissue. The specimen should include full-thickness epidermis and superficial dermis. The most common error when first performing shave biopsies is to remove only keratotic debris or the upper portion of the epidermis. The latter is especially true in areas with thick stratum corneum (e.g. palms, soles). Therefore, the dermatologist needs to appreciate the angulation of the blade that is required in order to obtain the full thickness of the epidermis plus some of the superficial dermis. Observation of the wound bed and review of the tissue sections will help refine the skills needed to perform this procedure. In a saucerization procedure, the depth of the biopsy specimen is intentionally deeper due to the angulation of the blade, which may or may not be attached to a handle (Fig. 146.8). Fat may even be included in the base of the specimen in sites with a thin dermis, but in general the biopsy extends to at least the mid reticular dermis. Both saucerization and shave biopsy sites heal by second intention. As with curettage and snip biopsy, hemostasis is easily obtained with a styptic, electrodesiccation, absorbable hemostatic sponge, and/or pressure. With practice and skill, as well as choosing the appropriate lesion to biopsy in this manner, the resulting mature scar is flat or slightly depressed with slight hypopigmentationPunch BiopsyPunch Biopsy A punch biopsy is routinely used to sample processes within the mid to deep dermis or depressed lesions. As discussed above, the volume of tissue obtained varies depending upon the diameter of the metal "barrel". For example, the specimen obtained with a 2 mm punch biopsy is very small and may not yield sufficient pathologic findings for an accurate diagnosis. In one study, however, where 2 mm punch biopsy specimens (examined by a dermatopathologist) were compared to excisional specimens, an accurate diagnosis (primarily AKs, BCCs, SCCs, inflammatory dermatoses) was made in 79 of 84 cases33. For most punch biopsies, an instrument with a 3 to 4 mm diameter is adequate. Occasionally, a 6 mm punch biopsy is performed to increase the likelihood of obtaining subcutaneous fat. However, as stated previously, the thickness of the dermis and the amount of subcutaneous fat required to establish the diagnosis must be kept in mind. Disposable punch biopsy instruments are generally used. Reusable stainless steel instruments are available but must be sterilized following each procedure and sharpened frequently. Toothed forceps, scissors, needle holder, and suture material are also required. Local anesthesia is achieved with either superficial or deep infiltration of the agent. An optimal aesthetic result is obtained when the round punch biopsy instrument is used to produce an oval-shaped defect that can be closed without "dog-ear" formation when sutured into a straight line parallel to the other skin lines in the region. While traction is applied by stretching or spreading the skin with the index finger and thumb of one hand in the direction perpendicular to the relaxed skin tension lines (see Fig. 142.6), the instrument is pushed into the skin and rotated in one direction with the other hand (Fig. 146.9). Back-and-forth twisting is not recommended as epidermis may be sheared off. Generally, the instrument is pushed and rotated until the subcutaneous plane is reached, as indicated by loss of the resistance encountered while cutting through the dermis. At times, the punch biopsy is utilized to just incise the skin superficially as when the skin is very thin (e.g. on the ear). The punch biopsy instrument is then removed and forceps are used (peripherally at one superficial edge) to gently extricate the specimen from the wound. Scissors may be needed to detach the base of the specimen, which can then be transferred to the appropriate container. In the case of fibrotic tumors or disorders, pressure may need to be applied to the surrounding skin to elevate the biopsy specimen. Although a punch biopsy wound can be left to heal by second intention after achieving hemostasis, the resulting scar is often depressed and takes several weeks to heal. Usually this wound is closed primarily, and the resulting scar is generally white or hypopigmented and has a linear or cruciate configuration. On the trunk or extremities, one or two simple interrupted epidermal stitches of 4-0 nylon or polypropylene monofilament suture achieve closure and hemostasis. On the face, neck or hands, the resulting scar may be less apparent if 5-0 or 6-0 simple interrupted sutures are utilized. Some physicians use fast-absorbing gut for patients who are unable to return for suture removal. However, it is also reasonable to have the patient return for a face-to-face discussion of the biopsy results, since the biopsy is being done to establish a diagnosis and determine a treatment plan. Sutures on the face are removed at 5-7 days, and on the trunk or extremities, at 10-14 days. A pathology report is usually available within 7 days. Table 146.11 highlights special considerations when performing a punch biopsy on the face.Incisional BiopsyIncisional Biopsy Large lesions in which the characteristic pathology is within the dermis or subcutis are often biopsied via an incisional or wedge biopsy (Fig. 146.10). The specimen may be entirely lesional or may contain an edge of clinically normal skin, which allows comparison of involved versus uninvolved skin as well as examination for any microscopically apparent early changes at the edge of the lesion. The goal is to obtain a wedge of tissue 3-4 mm wide and as deep as necessary. The tissue should be in one piece for accurate orientation of the specimen during preparation; depending upon the possible diagnoses, longitudinal sectioning may be requested. The length of the wedge varies, but should be long enough to avoid cutaneous cone formation in the final closure. Local anesthesia is obtained by deep and slow infiltration of the agent. It is advisable to wait 10 to 15 minutes after instillation to allow for complete anesthesia and to obtain the maximal vasoconstrictive effect of epinephrine. With a #15 blade (mounted on a blade handle) held perpendicular to the skin surface, a superficial incision into the epidermis scores one long side of the wedge using a light touch and one long motion, facilitated by traction by the non-dominant hand or an assistant. The second, long side is then scored similarly. These lines are then redrawn with the blade held in the same manner but with firm pressure, incising into deep tissue, first one side, then the other. The incision is continued until the desired depth has been reached, usually in one or two more cutting movements. The incision is angled toward the center axis so that deep within the tissue, the two incisions meet and complete the separation of the tissue. A forceps is used to lift the tissue out of the wound. If the tissue is still connected at its base, the blade or tissue scissors may be used to complete the detachment. Hemostasis is best achieved by point electrocoagulation. Large arterioles may require tying off with absorbable suture. An incisional biopsy wound is generally closed with suturing. In some circumstances, such as a site compromised by necrosis or infection, second intention healing may be the best option, even if it is slow and prolonged (see Table 146.8). Deep interrupted stitches of absorbable suture material, 4-0 or 5-0 in caliber, with the knot inverted are utilized to close the subcutis and the dermis (see Fig. 146.4). The epidermis is then closed with simple interrupted sutures of nylon or polypropylene monofilament. The size of the epidermal suture varies depending upon the site; the face is generally closed with 6-0 suture and other sites by 4-0 or 5-0 suture.Excisional BiopsyExcisional Biopsy (Excision in toto) Excision represents the workhorse of dermatologic surgery34. The procedure is designed to remove entire lesions for histopathologic examination as well as for surgical cure. Lesions such as a clinically typical BCC or an unsightly or troublesome subepidermal lesion presumed to be benign are commonly biopsied as well as excised in this fashion (Table 146.12). Atypical pigmented lesions highly suspicious for invasive melanoma are typically excised in toto as a biopsy procedure because the degree of atypia and depth of invasion may not be uniform; the excision allows the pathologist to examine the entire lesion and decreases the likelihood of sampling error. In addition, excision is frequently the treatment of choice after the diagnosis of a cutaneous malignancy has been established by a previous biopsy. The excision specimen is again submitted for histologic examination in order to confirm the diagnosis and for comment as to whether the margins of the specimen are clear of tumor. Some surgeons will place a nick or a suture in one edge of the specimen to assist in orientation. Although the basic concepts discussed above with regard to an incisional biopsy also pertain to this procedure, an excision in toto is more complicated because it is intended to be the final definitive procedure. Therefore, margins required for cure, as well as cosmetic and functional challenges with respect to the final scar, must be carefully considered in advance. Recommended margins for removal of an entire lesion depend on the clinical diagnosis. Most benign lesions can be removed completely by including a 1-2 mm margin of normal-appearing skin around the circumference of the tumor. A clinically well-demarcated, small BCC or SCC is generally, though not always, cured with 4-5 mm margins35,36. Atypical nevi are frequently excised with 3-4 mm margins. While 4 mm may not be required for complete removal of the lesion, it may save some patients from a second procedure, since it is standard practice to re-excise a nevus with severe atypia that is still present at the margins microscopically. The suggested margin for melanoma in situ is 5 mm although excision of lentigo maligna may require wider margins. For invasive melanoma, the recommended margin depends on the Breslow depth, e.g. 1 cm margins for tumors ≤1.0 mm in depth (see Ch. 113). The depth of the defect to be created must also be planned in advance37. Primary closure is facilitated when the base of the surgical wound lies within subcutaneous fat. In the case of melanomas, the excision should include full-thickness skin and subcutis and be down to fascia at its base. Although an excision is often referred to as an ellipse, the actual shape is fusiform (Fig. 146.11). The optimal geometry of the wound varies depending on the contour of the site and the elasticity and thickness of the skin38. The angle at each end of the excision varies from 30 to 75 degrees39. In order to minimize standing cone formation, each side of the fusiform shape is three to four times as long as it is wide. The central axis becomes the line of closure and dictates where the surface scar will be visible. A mature scar should appear as a thin line, although some spreading may be seen on the upper trunk and shoulders. From a cosmetic standpoint, an optimal scar results when the line of closure is placed within major skin folds, relaxed skin tension lines, wrinkles, or boundaries between distinct cosmetic units (see Ch. 142). Movement of underlying muscles may distort the line of closure, but this can be predicted in advance and the excision plan adjusted. For hair-bearing areas, the line of closure should follow the normal patterns of hair growth.More Excisional BiopsyThe process of excision and repair can be divided into a series of steps (Fig. 146.12, Video 146.1). Local anesthesia is best obtained by injection into the subcutaneous tissue. The planned excision, which is delineated with surgical marking dye prior to injection, is ringed by the anesthetic agent, with the needle pointed outward to include the area needed for undermining. After ensuring that anesthesia has developed, the site is cleansed and draped with sterile towels or drapes. The excision is begun by stabilizing the site either with the non-dominant hand or by an assistant. As with an incisional biopsy, the epidermis is scored on both sides by drawing lightly with a #15 blade (mounted on a blade handle) along the lines chosen to create the fusiform shape. With continued traction, the incision is completed to the base of the wound by drawing the blade with increased pressure. Unlike with the incisional biopsy, the blade is held vertically throughout the procedure so that the edges of the wound are perpendicular to the skin surface, not angled inward to create a wedge. Completing the incision in one to two strokes after scoring minimizes ragged edges. Care is taken at both apical angles to completely incise to the same depth as that reached at the center of the wound. When the fusiform incision is complete, to either the level of the subcutaneous fat or the fascial plane, the specimen sits up from its base like an island. The specimen is then dissected from the base of the wound using scissors or a blade and the specimen is transferred to the appropriate container. The end result of the excision is a fusiform-shaped wound with vertical sides and a flat even base consisting of subcutaneous fat or fascia. Hemostasis is achieved by electrocoagulation. The remainder of the procedure deals with the creation of a cosmetically acceptable and functional closure. In order to free tissue for movement into the wound, undermining is performed at the edges of the wound with either scissors or a scalpel. A favorite technique is to use scissors with rounded tips for insertion and then spreading of the tissue to produce blunt dissection in the plane of undermining, a procedure advocated because of the belief that it is less likely to cut arteries or nerves. Using the same scissors, but with a snipping or cutting motion to sharply dissect, is also safe and more effective in generating a smooth, less ragged unit of skin40. Sometimes, the two techniques are combined, with spreading followed by snipping of the intervening tethering strands. Undermining can also be done with a blade, sweeping horizontally from the depth of the wound into the surrounding tissues. Regardless of the technique chosen, undermining is done in a controlled fashion, and good exposure and visualization is achieved by maintaining adequate hemostasis as the dissection proceeds. Tactile confirmation of the position of the tips of the scissors is also helpful. In order to fill the defect with skin that matches with regard to thickness, the level of undermining is almost always at the same depth as the base of the wound, i.e. within the subcutaneous fat or at the fascial plane. Rarely, when there are superficially located arteries and nerves to be avoided, the plane of undermining is more superficial than the base of the wound. The use of curved scissors with the tips pointed upwards may facilitate staying in the appropriate plane.The goals of undermining are to mobilize a unit of skin to be moved into the defect41 in order to reduce wound closure tension42, to allow proper wound edge eversion43, and to provide a wide area for distribution of redundant tissue over the base of the wound. Undermining around the entire wound to a distance that is at least the diameter of the wound may be required to meet these goals. When little undermining is done, apposed wound edges are pulled inward and redundant tissue bunches up in the wound bed. This redundant tissue has a force and mass that may apply pressure to the healing wound, producing a situation that allows for maturing scars to spread out (Fig. 146.13). During closure, wide undermining disperses the redundant tissue over a large area of wound bed. It may also serve to create a plate-like horizontal scar that distributes the forces of contraction and stabilizes the final result (see Fig. 147.2). Undermining must include the apical angles, where it facilitates the rotation that occurs as the two sides of the fusiform shape are brought together. The adequacy of the width of undermining can be tested either by picking up both wound edges with toothed forceps or skin hooks and opposing them or by placing a large temporary suture. The temporary suture may also supply some intraoperative tissue expansion that will facilitate closure. Braided polyester (e.g. Ethibond®) suture is commonly used for this purpose since it is soft and will not cut through tissue. If, with these tests, the wound edges cannot be draped easily for closure, undermining can be extended. Once undermining is adequate and after again ensuring that the wound is dry, subcutaneous and epidermal sutures are placed to complete the closure. As with the incisional biopsy, deep interrupted stitches of absorbable suture material (4-0 or 5-0 in caliber, with the knot inverted) close the subcutis and the dermis. If the wound is thick or under tension, optimal closure may entail two layers of subcutaneous stitches (i.e. a complex layered closure). The epidermis is then closed with simple interrupted or running sutures with a smaller caliber. For a fusiform excision in toto, the end result of the procedure is a straight or curved line of closure that has the wound edges completely apposed and everted. The line of closure sits above the surrounding skin, sometimes described as having the appearance of the ridge line of a tent or a mountain range. The healing of a tensionless everted wound edge results in a flat, hairline scar.Cutaneous cone repairCutaneous Cone (Dog-Ear) Repair Closure of a fusiform excision may create cutaneous cones, i.e. tissue redundancies that distort the normal contour of the skin at the apical angles44. These cutaneous cones are also referred to as "dog-ears" and may consist of standing cones, lying cones, inverted cones, or protruding cones. Inverted cones can be the most difficult to diagnose, as the appearance is that of a subtle dimple rather than a protrusion. Regardless of their subtle nature, these redundancies will distort the final scar unless they are repaired. Cutaneous cones are also produced by tissue movement during flap closures. Standing cones primarily result from geometric factors (Fig. 146.14). They may appear in closures of fusiform excisions (with sides of equal length) when the sides are of insufficient length compared to the width of the excision. The resulting apical angles are too wide to rotate in and maintain a flat contour to the skin surface. For this reason, linear closure of a circle, an oval, or an ellipse will always create standing cones. Also, cutaneous cones always form during closure of fusiform shapes that have sides of unequal length; redundant tissue becomes apparent on the longer side. Notably, when an excision is performed on a convex surface, standing cones may occur despite seemingly small apical angles. With suture placement, collagen bundles are pulled together and act as rigid rods that will not lie flat on a curved surface. In addition to geometric forces, protrusions are produced when there is excessive subcutaneous tissue in the base of the wound at the apices (as compared to the center of the wound). A lack of adequate undermining at the apices will then magnify these protrusions. This process is usually called "boating" or "pseudo dog-ear" formation. It is important to distinguish boating from true standing cone formation because repair of the former requires removal of the excess subcutaneous tissue and appropriate undermining as opposed to the techniques described below. Many standing cones are small and can be repaired via a closure that employs the rule of halves (Fig. 146.15). The midpoint of each side is apposed with a suture, bisecting the wound. Each unclosed half is then bisected again and the closure is continued until all tissue has been apposed. For a fusiform shape with unequal sides, repair of standing cones in this manner produces a curved line of closure. The curvature is directly proportional to the size of the dog-ear. If the wound is in a site such as the forehead, which lacks loose tissue to free up and mobilize, the line of closure may remain straight; however, there will be noticeable gathering on one side of the line and a depressed contour on the opposite side of the line where the skin is thinned as it was stretched to fit.Simple straight, curvilinear, or angled excisions of standing cones will also restore the desired contour of the site, even though they lengthen the scar (Fig. 146.16). The first step is to close the center portion of the wound with subcutaneous sutures. It is helpful to continue to appose subcutaneous tissue from the center of the wound outward until the standing cones become visible. Epidermal sutures may also need to be placed since any gaping at the center of the wound will underestimate the size of the dog-ears. After undermining, one limb of the standing cone is cut through to the base of the wound along the line that is desired for final closure. Undermining is repeated until the excess tissue can be draped over the cut edge. The new apical angle will lie flat if the limb has been adequately cut and if undermining has been sufficient. The second limb of the standing cone is then addressed by cutting from the wound to the new apical angle. The excess tissue that is removed will be in the shape of a triangle that is referred to as a Burow's triangle45. An alternative method, helpful for novices wanting to create a straight closure, is bisection of the standing cone, laying each half out along the skin surface and then cutting the two triangles of excess tissue. Closure is then completed with subcutaneous and epidermal sutures. An M-plasty is a dog-ear repair that shortens the total scar length (Fig. 146.17). Depending upon the site, M-plasty scars may also fit within prominent lines and folds more accurately. This procedure is particularly helpful in sites that are not flat. The first step, as above, is to close the center portion of the wound and adequately undermine the apical angle. Both lateral limbs are cut at an obtuse angle from the end of the wound to about halfway toward the apex of the redundancy. The excess tissue is then draped over the cut edge and an M is now apparent. Cutting from the central tip to the two new apical angles removes two pieces of tissue that are also triangular in shape. closure. The area of these two triangles is equal to the area of the single triangle that would have been removed had a simple excision of the standing cone been performed. If the central tip lies in a good position, then a standard closure is performed. If the tip needs to be advanced to approximate the wound edges and fill the defect, a half-buried horizontal mattress stitch (also called a tip stitch or three-corner stitch) is used (see Fig. 146.17E). Care must be taken with the three-corner stitch, as necrosis of the tip can occur with too much tension. A dog-ear may also be displaced to a distant site. After closure of the central portion of the wound, an incision is made perpendicular to the dog-ear to an appropriate site where there is enough redundant tissue such that it can be removed as a triangle (Fig. 146.18). Undermining is required over a wide area so that tissue can be moved without tension. This procedure is also referred to as a Burow's advancement flap (see Ch. 147). It is commonly used to avoid dog-ear repair in a free margin or in a cosmetically or functionally sensitive area. Finessing closure of fusiform excisions may require changing the axis of the line of closure so that the scar blends better with the prominent lines and folds of the site. Changing the axis will produce dog-ears that can be repaired by any of these methods.Variations/unusual situationsVARIATIONS/UNUSUAL SITUATIONS A disc excision (with straight or angled edges) may be performed either for biopsy purposes or for biopsy and definitive treatment. This option is chosen when healing by second intention is preferred46 or when it is desirable to remove the tumor first and then repair the dog-ears during the closure. Second intention healing may be advantageous when the risk of adverse reactions with primary closure is high. For example, excisions of even small tumors on the anterior lower leg that are closed primarily can produce wounds with tension and wounds that are more likely than those at other sites to dehisce, become infected, or be painful. This is especially true if undermining is inadequate and weight-bearing is not minimized for the first 5-7 postoperative days (including, at times, the use of crutches). Another option for wounds with too much tension on the anterior lower leg is the placement of a skin graft, but postoperative care requires leg elevation and the absolute avoidance of weight-bearing. Alternatively, the wound can be closed, either partially or completely, with a pursestring suture47,48. The latter is a running suture that is placed around the entire perimeter of the disc. After its placement, tension is applied to the ends of the suture until maximum constriction is obtained and then the ends are knotted. Advantages of the pursestring suture are speed, distribution of tension circumferentially, and amelioration of the need for the removal of excess normal skin in order to complete a fusiform excision. Since the time for complete re-epithelialization of a wound undergoing second intention healing is related to the diameter of the largest circle that can be drawn within the wound, even closure of a wound by 30% can result in a significant reduction in healing time. This smaller wound can also be grafted if desired. When wounds heal by second intention, postoperative care is less burdensome, as the patient may resume normal activities almost immediately while dressing and bandaging the wound daily. However, compared to a linear excision, re-epithelialization requires a significantly longer period of time; the latter varies directly with the size of the wound and can range from 2 weeks to at least 2 months on the distal lower extremities. The patient also needs to consider the resultant scar, i.e. a depressed circular scar versus a graft versus a linear scar. Removal of melanocytic nevi on the upper trunk and shoulders via disc excision or saucerization (angled edges) results in a smaller, often more cosmetically acceptable scar than does a fusiform excision. Also, the excision of tumors in sites such as the ear may be amenable to disc excision followed by second intention healing. Performing a disc excision and then repairing the dog-ears during the closure allows the surgeon to pay particular attention to the issue of appropriate curative margins without dealing simultaneously with the cosmetic and functional issues of the closure. Once the tumor has been removed and the area widely undermined, the line of closure can be determined, that is, the closure with the least amount of tension that fits into the dominant lines of the site49,50. The central portion of the wound is apposed by subcutaneous and epidermal sutures or by a large simple interrupted temporary suture and then the dog-ears are repaired. Since the cosmetic and functional issues are addressed after excision of the tumor and undermining, the resulting scar can be optimized. The shape of the excision can also be modified via a procedure known as an S-plasty51. Most useful on convex surfaces, this variation increases the total length of the scar while keeping the linear distance between the two apices constant. In a simple fusiform excision, the tension is located primarily in the center of the wound and is exerted along a single vector that is perpendicular to the axis of the wound. On the other hand, an S-plasty redirects and redistributes tension into multiple vectors along the wound, thereby minimizing tension in the center of the wound; in addition, the central tension vector is perpendicular to the primary tension vectors at the apices of the wound. Because much of the tension is displaced from the area of maximal convexity, the likelihood of a central depression or dehiscence is reduced.Postoperative carePOSTOPERATIVE CARE Wound care and bandaging both play an important role in minimizing the risk of complications and in obtaining optimal cosmetic and functional results. Wound care removes surface debris and promotes re-epithelialization. A good bandage supports and stabilizes the wound in the closed position, wicks away excessive blood or tissue fluid, supplies pressure to the wound for hemostasis, and protects the wound from the dryness and bacterial contamination of the external environment. A small shallow wound that is to heal by second intention is cared for by daily cleansing of the site with mild soap and water, application of petrolatum52 and coverage with an adhesive bandage such as a Band-Aid® (with a central nonadherent area). A liquid adhesive bandage has also been reported to be effective; in a trial focusing on minor cuts and abrasions, it proved easy to use53. A large shallow wound that is to close by second intention may need a bandage fashioned specifically for that site, usually consisting of layers composed of petrolatum, Telfa®, gauze or cotton, and tape or other means of adhering the bandage at the site. A layered bandage is also required for a sutured wound. A liquid adhesive (e.g. Mastisol®) is applied to the skin surface surrounding the sutures. Petrolatum is applied in a thin line onto the wound edge. Sterile tapes such as Steri-Strips™ are placed perpendicular to the line of closure. The final layer is rolled gauze or cotton, which is then taped in place with paper tape, Scanpor® tape, Kind Removal® Silicone Tape, or Hy-Tape® ("pink" tape). Elastic dressing (e.g. Coban®) can be used for compression, but should be released and reapplied if it is used circumferentially, so that vascular compromise distally does not occur. Patients need oral and written instructions regarding the care the wound will require at home. Most simple wounds are cleansed daily with soap and water and redressed until the sutures are removed or the wound has completely re-epithelialized. Patients should understand that they need to remove any crusting or debris from the wound as they cleanse it and they may prefer to use cotton-tipped swabs or gauze. Instructions regarding bandages should likewise be clear. Leaving the wound open to the air or allowing it to become dry retards re-epithelialization and may compromise the final appearance or the scar54. Bandages that minimize the need for wound care are preferred by many patients. In addition, the stability and protection afforded by a bandage that stays in place for a week or more may further optimize the results, especially for wounds closed primarily. These bandages may be constructed in layers as discussed above and should be kept dry to prevent maceration of the covered skin. On the trunk and extremities, a bandage can be made of a polyurethane foam dressing (e.g. Cutinova Hydro®) covered by a water repellent film (e.g. Bioclusive®), precluding the need for any care and allowing ease of movement and a normal regimen for bathing. Once the sutures have been removed and the wound cleaned, the use of liquid adhesive and sterile tapes for another week or two further stabilizes the wound. Many specialized bandaging systems are available for complicated woundsComplicationsCOMPLICATIONS Short-term complications of biopsies and excisions are few in number and generally engender limited morbidity (Table 146.13)55. In addition, the smaller the procedure, the fewer the complications, which explains why shave biopsies and snip biopsies are quite safe. Hemorrhage may occur, from the time of the procedure to afterwards when the patient has returned home, and it usually occurs within the first 24 hours. Although many patients take aspirin, warfarin or other agents that affect coagulation or platelet function, hemostasis can be achieved during the procedure, resulting in few adverse bleeding events56. Infection occurs rarely, i.e. in <1% of most procedures57. Some patients develop irritant or allergic contact dermatitis due to topical antibiotics58 or to tapes and bandages. These reactions are managed with a change in the wound care regimen but do not usually require topical corticosteroid creams. Rarely, application of neomycin or bacitracin can produce contact urticaria. Biopsies performed on the lower limbs, limbs affected by lymphedema, intertriginous areas, and ears are most susceptible to infections. If an infection develops, oral antibiotics may be required. Pain is generally minimal. When it occurs 3-5 days after the procedure, infection is the most likely cause, even in the absence of erythema, tenderness, and purulence. Very rarely, paresthesias may result and can persist for several months, especially on the forehead. Wounds that are closed primarily may dehisce because of tension, hematoma formation, poor wound healing, or infection. These wounds are thereafter managed for second intention healing and a delayed reconstruction can be undertaken, if needed, when the attendant inflammation has resolved. Long-term complications (see Table 146.13) generally consist of functionally or cosmetically adverse scarring59. Depressed scars may occur if not enough subcutaneous tissue is brought into the line of closure. Atrophic and widened scars occur in areas where there is intermittent stretching of the scar as it overlies major muscle groups. Careful surgical technique that includes adequate undermining, minimization of tension at the line of closure, and the use of multiple subcutaneous sutures can reduce the likelihood of this complication. Scars may pursue a prolonged course of healing with erythematous thickening at the line of closure. These hypertrophic scars do resolve with time. To speed their resolution, practitioners often advise massage or inject triamcinolone acetonide (10-40 mg/ml) into the scars. Silicone dressings are also recommended, but they are probably no more effective than non-silicone gel dressings60. In addition, scars may have a fragile surface (due to reduced dermal-epidermal attachments), pruritus or paresthesias, most of which resolve with time. A true keloidal scar is one that grows beyond the boundaries of the original surgical injury and appears as a thickened erythematous or hyperpigmented nodule or plaque (see Ch. 98). It occurs in predisposed individuals who may have a history of previous keloid formation. Keloidal scarring is most commonly observed when procedures are performed on the upper trunk and shoulders and may be very difficult to treat.