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Management of early lentigo maligna and lentigo maligna melanoma of the head and neck
Facial Plast Surg Clin N Am 11 (2003) 93 – 105
Management of early lentigo maligna and lentigo maligna melanoma of the head and neck Kenneth W. Anderson, MDa, Shan R. Baker, MD, FACSb,* a
Department of Otolaryngology-Head and Neck Surgery, University of Michigan Hospitals, 1500 East Medical Center Drive, TC 1904, Ann Arbor, MI 48109, USA b Department of Otolaryngology-Head and Neck Surgery, Division of Facial Plastic and Reconstructive Surgery, Center for Facial Cosmetic Surgery, University of Michigan Medical Center and Comprehensive Cancer Center, 19900 Haggerty Road, Suite 103, Livonia, MI 48152, USA
As the general public becomes increasingly educated about health matters, melanoma has earned a reputation as a lethal disease to be feared. Although it is less common than squamous cell and basal cell carcinoma, the mortality rate for patients with melanoma is significantly greater. As many as one third of melanomas occur on the head and neck. For this reason, the facial surgeon must be familiar with the disease, especially with regard to management of early lesions. The chance for cure is high if melanoma is detected early and treated appropriately, usually through surgical resection. Advanced melanoma carries a worse prognosis, regardless of treatment. This article reviews the clinical and histopathologic characteristics of melanoma. Atypical junctional melanocytic hyperplasia and its significant role in the surgical management of melanoma of the head and neck is discussed. In addition, the principles of managing the most common melanoma subtypes located on the head and neck, lentigo maligna (LM) and lentigo maligna melanoma (LMM), are discussed. A staged excision technique called the ‘‘square’’ procedure is used for LM and LMM and features 100% peripheral margin control before reconstruction of the defect. Principle methods of reconstruction are reviewed, and two case illustrations are provided [1,2].
Epidemiology Melanoma continues to present a significant public health problem; the number of new cases of melanoma is rising at a rate that is higher than that of any other cancer [3]. In the 1930s, the lifetime risk of an American developing melanoma was 1 in 1500 [4]. Estimates place the lifetime risk for Americans born in the year 2000 at 1 in 75; those born in 2010 will face a lifetime risk of 1 in 50. It has been further estimated that 53,600 cases of invasive melanoma and 34,300 cases of melanoma in situ will be diagnosed this year in the United States [5]. Despite the rising incidence, there has been an increase in the 5-year survival rate [6], which is approximately 80% to 90% compared with about 40% in the 1940s. This increase is attributable to public and health care provider awareness that results in earlier detection of lesions. The effectiveness of surgical excision for primary melanoma has not changed significantly over this same time period. Because of the exponential increase in incidence, the death rate from melanoma continues to climb despite improved survival rates. In 2002, the number of deaths that were attributable to melanoma in the United States was estimated to be 7700, or about one death every hour.
Etiology * Corresponding author. E-mail address: [email protected] (S.R. Baker).
Genetic and environmental factors are involved in melanoma development. The most widely accepted
1064-7406/03/$ – see front matter D 2003, Elsevier Science (USA). All rights reserved. doi:10.1016/S1064-7406(02)00053-6
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predisposing environmental risk factor for the development of melanoma is exposure to ultraviolet light, primarily from sunlight. Excessive lifetime exposure, intermittent exposure, artificial light sources (sunlamps), and a history of blistering or peeling sunburns are associated with an increased risk. Many investigators now believe that intermittent acute exposures are more damaging than cumulative exposure, especially exposures acquired during childhood through young adulthood [7]. Approximately 70% of melanomas are sun-related, with an unknown cause in the other 30%. Several other known risk factors associated with melanoma include the presence of dysplastic nevi, more than 100 normal moles, inability to tan, previous personal or family history of melanoma, and fair skin type, especially in association with blue eyes and blonde or red hair [8].
Recognizing melanoma Roughly one half of melanomas arise in a preexisting nevus, with the remainder arising in previously unaffected, normal-appearing skin. The ABCDs of melanoma may provide clues that a benign nevus has transformed into melanoma. ‘‘A’’ stands for lesional asymmetry; ‘‘B’’ is for border. Lesions with asymmetrical, scalloped, or indistinct borders should raise clinical suspicion. ‘‘C’’ stands for color; lesions that display intensely dark pigment, or shades of red, white, or blue are more closely associated with melanoma. ‘‘D’’ is for diameter; lesions larger than 6 mm in diameter are more concerning.
Histopathophysiology and prognostic variables Every melanoma begins with a proliferation of melanocytes. Initially the proliferating cells appear as nests of atypical melanocytes at the epidermal-dermal junction. The rate and characteristics vary in their progression from a small focal area of neoplastic cancerous melanocytes to a vertically invasive, potentially metastatic melanoma. As these nests of cells proliferate, melanocytes also scatter upward into the epidermis, the so-called ‘pagetoid’ pattern of spread. The melanocytes within the tumor display a uniform, atypical appearance that features nuclear atypia, prominent nucleoli, mitosis, and increased cell size. If confined to the epidermis, the lesion is considered melanoma in situ. A transformation to invasive melanoma occurs when the basement membrane of the epidermal layer is breached as the atypical melanocytes grow down into the dermis. A radial growth
phase was described [9] wherein the atypical cells proliferate in a progressive horizontal centrifugal pattern along the epidermal – dermal junction. This occurs for a variable length of time, depending on the histological pattern of the melanoma. The radial growth phase is followed by the vertical growth phase, during which the atypical melanocytes grow deeper into the dermis. Often this is heralded by ulceration, bleeding, and nodule formation. The mean age at time of diagnosis is 50 years for women and 55 years for men [10]. Patients can and do present at any age, however, often with a history of a slowly evolving change of a precursor lesion over the previous 1 to 5 years. Classically, four subtypes of melanoma are described, and are divided according to histological growth patterns. These subtypes include superficial spreading, nodular, acral lentiginous, and lentigo maligna. Superficial spreading melanoma is the most common histologic subtype and represents 70% of all melanomas. There is a characteristic initial radial growth phase that is followed (after a variable amount of time) by the vertical growth phase with associated ulceration, bleeding, and nodule formation. Nodular melanoma is the second most common type and accounts for 15% of all melanomas. The main feature that separates this lesion from a superficial spreading melanoma is the minimal intraepidermal involvement at the periphery of the tumor. Unlike superficial spreading melanoma, the nodular form may display a short radial growth phase (if any at all) and proceeds to the vertical growth phase earlier in the development of the lesion, with the associated nodule formation, ulceration, and bleeding. Acral lentiginous melanona displays histologic features and clinical behavior that is also similar to the superficial spreading subtype. These melanomas are unique because of the location of the tumor on the palms, soles, nail beds, and oral mucous membranes. They appear most commonly on the plantar surface of the foot and is the most common subtype in the black population. Lentigo maligna melanoma most commonly occurs on the head and neck [7] and represents 10% to 33% of all melanomas in this location [11]. It has several characteristics that distinguish it from the classic superficial spreading subtype that are discussed in detail below. In the past, it was believed that each growth pattern represented a different subtype of melanoma, each with a unique patient profile, pattern and rate of growth and invasion, preponderance for metastasis, and prognosis. Accurate pathologic interpretation of a biopsy specimen is critical to
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determining treatment and prognosis for melanoma. Significant prognosis variables include histologic subtype, depth of invasion, anatomic site, mitotic rate, growth phase (radial vs. vertical), and the presence or absence of ulceration, host inflammatory response, angiolymphatic spread, and a precursor lesion [12]. Tumor thickness is the best predictor and single most important factor in determining prognosis and appropriate management of patients. The status of ulceration has proven to be another highly significant prognostic factor. The histologic subtype of the melanoma was reported to influence prognosis; nodular and acral lentiginous patterns have a worse prognosis than other types. After adjustment for tumor thickness, however, the unfavorable prognostic association disappears [13].
Lentigo maligna melanoma Lentigo maligna melanoma has several characteristics that make it unique. Almost all LMM lesions occur in areas of chronic sun exposure and typically are located on the face; the nose and cheeks are the most common sites. Lentigo maligna is a melanoma in situ and may appear as a light brown macule that develops in chronically sun-damaged skin. Its appearance has been likened to a stain on the skin. LM lesions often have a prolonged radial growth phase, which may last for decades. As such, LM usually develops in older individuals; the average age of diagnosis is approximately 65 years of age and these lesions are uncommon before the age of 50. The classic histologic characteristics of LM lesions include an increased number of atypical basal layer melanocytes with intraepithelial growth that extends along the cutaneous adnexal structures, especially the hair follicles and sweat ducts deeper in the dermis. These findings are seen within a background of solar elastosis and chronic sun-damage changes, as evidenced by atypical junctional melanocytic hyperplasia (AJMH). After a protracted radial growth phase, invasion into the papillary dermis signals the invasive phase and signifies the transformation to LMM. Vertical growth phase progression may be evident clinically by the appearance of one or more nodules within the macular lesion. The fraction of LMs that progress to LMM is unknown, but estimates have placed the lifetime risk of malignant degeneration at 5% to 50% [8,14]. Some investigators believe that transformation from the in situ LM to the invasive LMM will eventually occur in all lesions if the patient lives long enough [8].
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Atypical junctional melanocytic hyperplasia Subtle features distinguish normal background melanocytic upregulation secondary to chronic photo-damage, scarring, or inflammation from atypical junctional melanocytic hyperplasia. The distinction requires a dermatopathologist with extensive expertise and experience, as well as clinical correlation. AJMH is characterized by melanocytic hyperplasia with random varying atypia of single cells at the epidermal – dermal junction with frequent deeper extension down adnexal structures. AJMH may display a significant degree of cytologic atypia, mitotic figures, and areas of continuous, lentiginous proliferations and nests. With increasing degrees of melanocytic atypia, there is a continuous progression of AJMH with slight, moderate, and severe atypia. The terms ‘‘AJMH with severe atypia’’ and ‘‘lentigo maligna’’ can be used interchangeably, as they refer to the identical in situ melanoma lesion. LM lesions display a region of central marked atypia that merges with less prominent AJMH at the periphery of the lesion. Usually, there is no distinct clinical margin to the atypia making the evaluation of the peripheral margins of LM/LMM especially difficult, as the AJMH progresses from marked to moderate to slight atypia. Moreover, an unpredictable subclinical extension of AJMH is predominantly associated with the LM/LMM subtype. The peripheral AJMH extends beyond visible margins and Wood’s lamp margins. It can be further camouflaged on the head and neck by freckles, pigmented actinic keratoses, lentigines (sun spots), nevi, or seborrheic keratoses [15]. Unresected AJMH may recur as LM (in situ melanoma) and less frequently, as invasive melanoma. Although rare, these local recurrences may develop rapidly (less than 1 year) and are associated with an increased rate of metastasis and a worse prognosis (Fig. 1). Thus, accurate interpretation of lesional AJMH/LM is critical when evaluating surgical margins when an LM/ LMM lesion is exercised. With the increasing emphasis on the diagnosis of early melanoma, the distinction between AJMH and upregulation of melanocytes in sun-damaged skin creates special challenges in the management of LM/LMM on the head and neck.
Destructive treatment modalities Although surgical excision has been the traditional treatment for LMM of the head and neck, other treatment modalities exist. These alternative methods, reported for use with LM but not LMM,
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destruction must extend to the base of the adnexal structures in the middle to deep dermis, and sometimes fat, to minimize the chance for local recurrence. Additionally, cryosurgery and laser ablation have the added disadvantage that they may destroy the melanocytes’ ability to make pigment, which will make a local recurrence amelanotic. Such recurrences are obviously difficult to detect early and monitor. Destructive modalities may be useful for smaller lesions in selected patients or areas without adnexal structures, such as oral mucosa; however, surgical excision with meticulous histologic margin control results in the highest cure rate for LM and LMM and is the preferred treatment [8,17,18,20].
Surgical treatment modalities
Fig. 1. The recurrent melanoma with satellitosis shown here developed in the site of an incompletely resected lentigo maligna lesion. The original lesion demonstrated atypical junctional melanocytic hyperplasia with slight atypia to the peripheral margins. Note the scar in the central portion of the melanoma corresponding to the previous resection. Unresected AJMH resulted in a rapidly growing, locally recurrent, invasive lesion 8 months after initial resection. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:20 – 6; with permission.)
The highest chance for cure is realized through total surgical excision of the primary lesion and with total peripheral margin evaluation and control. The current recommendations for surgical margins for lesions not on the head and neck are 0.5 cm for in situ melanoma and 1 to 2 cm for invasive melanoma, depending primarily on tumor thickness and the presence or absence of ulceration. These recommendations, especially for the LM/LMM subtype on the head and neck, however, are usually not adequate because of frequent subclinical extension of AJMH. Studies showed that for LM on the head and neck, the average margin required for clearance was 8.3 mm; margins of 15 mm were required to clear 96% of tumors. For LMM, an average margin of 11.8 mm was necessary for clearance, with fully 26 mm margins required to clear 95% of lesions [22].
Margin control involve the destruction of the superficial lesion using cryosurgery, radiotherapy, electrodesiccation and curettage, laser surgery, topical 5-fluorouracil, and azelaic acid [8,16 – 21]. The local recurrence rates using these techniques are high, and range from 20% to 100% [8,17]; this is largely because of the atypical junctional melanocytes that extend down and around the hair follicles and sweat glands that often are not effectively treated using destructive modalities. Other disadvantages include the lack of a specimen for the dermatopathologist to use to assess peripheral margins and to examine histologically. Thus, there is no way to detect any subclinical peripheral extensions of AJMH. In addition, there is no way to detect an invasive component of the primary lesion [13]. If such treatment modalities are selected, the tissue
The goal of surgery is to excise the lesion completely following a fundamental oncologic principle, tumor clearance first, and defect reconstruction second. The cosmetic and psychological significance of the face, as well as the presence of vital structures make the preservation of normal, uninvolved skin an important issue. A search for accurate and precise margin control led surgeons to explore alternatives to standard surgical excision with wide margins, such as Mohs micrographic surgery with and without immunostaining, and Mohs surgery with rapid permanentsection processing [18 – 22]. Using these approaches, the reported local control rates are in the range of 90% to 99%. These alternatives, all of which stem from basic Mohs surgery technique, may rely on
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frozen section interpretation of margins and require considerable training to achieve proficiency. The frozen sections must be of exceptional quality and examined by an experienced dermatopathologist or Mohs surgeon to accurately interpret melanoma margins. The addition of immunostaining may improve accuracy, although this is a labor-intensive process and the benefit is highly debatable [22]. Permanent formalin-fixed sections are easier to process and interpret and are superior in quality to frozen sections for melanoma [16]. Taking standard, frozen sections for melanoma margins in the operating theater setting is not dependable and is not recommended [23]. Evaluation of surgical margins for AJMH is nearly impossible on standard, frozen sections because of the artifacts that are created during the freezing process [24,25]. Unresected AJMH may eventually present as LM or invasive LMM recurrences. Therefore, every effort should be directed toward complete excision of the primary lesion with all of the peripheral lesional AJMH. Our experience in treating LM/LMM subtype lesions in the 1980s and early 1990s, with standard Mohs and surgical excision using standard bread loaf permanent section processing for ill-defined lesions at the University of Michigan, was associated with an unacceptable recurrence rate. Because of this, we developed a different approach to these lesions that is relatively simple, technically easy, and more comfortable for the patient. The procedure is staged; total (100%) peripheral margin evaluation is achieved during each stage. Tumor clearance is attempted at the initial stage, with re-resection of positive areas as required (stages 2, 3, and so forth). Excision of the central lesion with reconstruction of the defect is performed as a final stage, only after all margins have been cleared. This technique, known as the ‘‘square’’ procedure, uses permanent formalin-fixed histologic sections (slides) with theoretical total peripheral margin control.
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edges of the margin are straight, with geometric, sharp-angled corners. Thus, a shape such as a square, rectangle, or diamond is usually marked around the lesion. The geometric configuration with angled corners facilitates tissue processing and precise orientation for total (100%) peripheral margin interpretation. If curvilinear incisions are used around the lesion, complete evaluation of the peripheral margins is possible, but requires additional small steps for tissue processing for total margin control. Local anesthesia is introduced into the skin and subcutaneous tissue along the planned margins. Using a two-bladed scalpel with two to four 1 mm spacers, a peripheral strip of tissue 2 mm to 4 mm wide is excised to the underlying adipose tissue (Fig. 2). The outer blade corresponds to the peripheral margin. This is performed along each of the marked linear margins, using a second single-blade scalpel to cut the peripheral tip corners. A ‘‘square’’ of tissue is removed en bloc from the patient. The tissue square, which contains 100% of the peripheral margin, is tagged with a suture for orientation. The resulting geometrically-shaped, excisional strip wound is sutured closed with a running nonabsorbable suture (Fig. 3). Thus, a relatively small strip of tissue around the periphery of the lesion is excised, and as a result, wound care is minimal. The central island of tissue that contains the lesion is left intact while the margins are assessed. The specimen is pinned to Styrofoam to prevent rolling of the edges, and is sent for histologic processing followed by dermatopathologic evaluation. The specimen is embedded in paraffin and routine vertical sections that contain 100% of the peripheral margins are processed. The specimen is inked and a simple cartoon map is included with the
The square procedure The clinical margin of the lesion is outlined, which may be aided by use of a Wood’s lamp in some cases. The Wood’s lamp (UV-A blacklight) may help to distinguish the subclinical extent of some lesions with visual identification of subclinical pigment. A margin is outlined at 0.5 cm to 1 cm from the clinically-apparent borders of the lesion, with the intent to establish margins that are free of lesional AJMH with the initial surgical procedure. The margin around the lesion is usually marked, such that the
Fig. 2. Use of a two-bladed scalpel with a 2-mm spacer facilitates excision of a thin strip of tissue. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:202 – 6; with permission.)
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Fig. 3. The purpose of the initial stages of the square procedure is to define the lesion perimeter. (A) After removal of a strip of tissue around the lesion, the excisional strip wound is sutured closed. (B) The tissue is processed to examine 100% of the peripheral margins. After the peripheral margins have been cleared, the central island of tissue is resected and the wound is reconstructed. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:202 – 6; with permission.)
specimen for precise anatomical orientation of the peripheral margins. The dermatopathologist examines the permanent vertical sections and notes any areas that are positive for melanoma or AJMH. Using the cartoon map, any remaining positive areas are reexcised in a similar fashion and sent for permanent vertical sectioning as described earlier. This process is repeated until all of the margins are free of lesion. When the entire peripheral margin is interpreted as being tumor free, the central island of tissue is excised within the defined clear peripheral margins and sent to the laboratory for serial sectioning and histopathologic evaluation for any invasive component. The reconstruction is performed with the confidence that 100% of the margin has been evaluated and interpreted as being free of melanoma.
Lentigo maligna melanoma Nodularity, ulceration, or bleeding from a central area within a LM lesion is suspicious for invasive LMM, and therefore, is excised at the first stage of the square procedure to reduce the risk of further invasion and metastasis. In such cases, the lesion is completely excised with only 1 mm to 2 mm margins for diagnostic purposes and microstaging. Wider margins are subsequently obtained using the square procedure. If the melanoma approaches 1 mm in
Breslow depth, excision of the primary melanoma and sentinel lymph node biopsy is performed at the same time. For lesions that are too large to completely excise in the office, an incisional biopsy of the majority of the lesion and any elevated portions is recommended. Primary closure of this central portion is performed after the sentinel nodes have been found and removed from the patient. The peripheral margins are subsequently cleared for local control using the square procedure if necessary. In histologically equivocal cases, or in patients with severely sun-damaged skin, a random punch biopsy may be taken from the opposite side of the face to help determine normal background melanocytic morphology.
Full square technique If reconstruction of the resected tissue will likely consist of a delayed, full-thickness skin graft, the entire lesion is excised during the first stage. This can be useful in concave facial areas, such as regions of the nose. The peripheral margins are evaluated as described earlier, and the center of the specimen, removed at the initial stage, is serially sectioned and evaluated for any invasive melanoma. The wound is left open to granulate for 1 to 4 weeks to allow formation of a well-vascularized recipient tissue bed that enhances graft survival and creates a more superficial wound that lessens or eliminates contour deformities.
Clinical experience We have used the square procedure since 1994 on hundreds of patients. Follow-up periods of 5 to 10 years are needed to accurately determine the local control rate with the square procedure using a prospective database, but thus far we have experienced only rare recurrences. The square procedure has the benefit of visualization and interpretation of 100% of the peripheral margins, with high-quality, permanent, formalin-fixed histologic analysis. Conservation of tissue is also achieved, which is particularly important when resecting tissue from the face. The technique is a simple, relatively quick, multidisciplinary method that results in high local control rates of LM/ LMM on the head and neck. The facial plastic surgeon can proceed with reconstruction at the time of excision of the primary lesion with the knowledge that the entire peripheral margin has been examined and that the risk of recurrence is minimal.
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Reconstruction Following the square procedure, most patients undergo reconstruction using local skin flaps. Usually transposition or advancement flaps are used and may be combined with full thickness skin grafts for large excisions. Advancement flaps If the defect is small enough, then a simple advancement flap is used. Advancement flaps are created by incisions that allow for a ‘‘sliding’’ movement of the incised tissue. The incisions are usually parallel to the opposite borders of the defect and extend away from the defect for varying lengths. The use of advancement flaps results in primary and secondary tissue movement [26]. Primary movement refers to the pulling, sliding, or pushing of the elevated tissue toward the defect. There is also a small amount of stretching of the flap itself. Secondary movement is the pull of native tissues in a direction opposite to the primary movement. The result is that surrounding skin and soft tissues adjacent to the defect are pulled toward the defect. Secondary movement can sometimes be beneficial because it provides less woundclosure tension and aids in wound closure. Secondary movement is detrimental when the wound is located near a free margin of a facial structure. The resulting pull on structures, such as the lower eyelid, will result in undesirable distortions.
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Advancement flaps always create two standing cutaneous deformities (SCD). These typically require excision by removal of Burow’s triangles, which may also facilitate movement of the flap. Advancement flaps often involve some degree of pivotal movement. The laterally-based cheek advancement flap, for example, relies primarily on the sliding of loose cheek tissue from the lateral to the medial aspect of the face and involves a smaller magnitude of inferior to superior pivotal (rotational) movement. A key advantage of advancement flaps is the ability to excise SCDs anywhere along the entire length of the flap. The preferred location for excising Burow’s triangle is best determined after suturing the leading border of the flap in place. An effort is made to place the incision lines for the Burow’s triangle in the appropriate relaxed skin tension lines (RSTLs) or a cosmetic boundary. For defects of the forehead, a single advancement flap or bilateral advancement flaps work well. The use of the horizontal RSTLs in the forehead and eyebrow region is well suited for camouflaging portions of the scar. The usual ratio of defect length to flap length is 3:1, although if the flap is based on a named artery, a ratio of 4:1 is possible [26]. To facilitate wound closure, greater tissue movement is gained from the temple area of the forehead compared with the more central region. Whenever possible, advancement flaps should be designed to recruit skin from this area. An O-T flap, or ‘‘T-plasty’’, transforms a round or triangular defect into a T-shaped scar. The defect is closed by advancing flaps in opposite directions from
Fig. 4. (A) Illustration of a T-plasty closure following the removal of a circular defect above the left eyebrow. The shaded areas are removed after the primary lesion is resected circular defect. Wedges of tissue are removed from the base of the wound at the perimeter of the circular defect. Superiorly, an M-plasty serves to shorten the vertical scar length. The shaded ‘‘M’’ superiorly, as well as the Burow’s triangles at each end of the horizontal limb of the flaps, are likewise removed. (B) Final appearance after closure of the wound. The horizontal limb of the T is camouflaged just above the eyebrow.
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Fig. 5. (A) Following removal of a circular lesion at the alar base, a triangular subcutaneous island pedicle flap is incised in the melolabial sulcus. The triangular, shaded areas between the circular defect and the planned wedge-shaped cutaneous portion of the flap are excised. (B) The skin flap based on a subcutaneous pedicle is advanced into the defect site with a skin hook. (C) Final appearance after the defect is closed in a V-Y fashion.
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either side of a triangular or circular-shaped wound (Fig. 4). One advantage of this type of repair is that the defect is repaired with two smaller flaps rather than one large flap. The tissue for wound repair is obtained from two separate areas which facilitates donor site closure. The incisions often can be placed in natural lines, creases, or at the junctional border of adjacent esthetic regions. T-plasty works well on the central forehead when the vertical limb can be placed in the midline. Other suitable locations for T-plasty closure include areas just above the eyebrow or the temple area adjacent to the hairline. In such cases, the horizontal limb of the T-plasty is placed along the border of the eyebrow or in the hairline. T-plasty also works well on the upper lip next to the vermilion and on the chin. In this instance, the horizontal portion of the T-plasty may be camouflaged by placing it along the vermilion border or the mental crease, respectively. An island V-to-Y advancement flap is well-suited for repair of medium-sized defects of the upper lip near the alar base. The pedicle of the flap consists of the underlying subcutaneous tissue. Undermining is
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performed around the periphery of the flap and defect to facilitate closure. As the flap is advanced on its subcutaneous pedicle toward the defect, the donor area is closed primarily creating a V to Y configuration of the wound closure line (Fig. 5). The size of the flap should approximate that of the primary defect; an effort is made to place the incision lines parallel to, or in the borders of, adjacent esthetic regions. For upper lip defects near the nasal sill, the lateral limb of the flap usually can be placed in the melolabial sulcus. Another advantage of this flap for defects of the lateral upper lip is that it permits reconstruction of the moustache in men, as the flap uses hair-bearing skin from the upper lip with proper orientation of the facial hair. This flap can also be used successfully for defects of the medial cheek. Transposition flaps Transposition flaps are a common method of repairing defects after the square technique is used on the cheek. Transfer of tissue is accomplished by
Fig. 6. (A) Patient following two stages of the square procedure for a lesion on the cheek. (B) Excision of central island of tissue and transposition flap designed for repair of wound is marked. (C) Intraoperative view of transposition flap following transfer. A FTSG was used to reconstruct a region of the wound near the lower eyelid; the source of the FTSG was the SCD created by the transposition flap. (D) Six-month postoperative appearance.
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Fig. 6 (continued).
moving the flap through an arc about a pivotal point located adjacent to a border of the defect. In essence, tissue is transferred from an area where it is more abundant to an area that requires resurfacing. A variety of design patterns, including the rhombic flap, banner flap, bilobed flap, and bilateral rhomboid flap, is a testament to the versatility of this method of reconstruction. An advantage of transposition flaps is the ability to design flaps with an orientation that results in minimal wound closure tension and maximum scar camouflage [26].
that is not closed by the flap. Additional incisions elsewhere on the head and neck are thus avoided, along with the obligatory donor site scarring and potential morbidity. If the SCD is not sufficient to repair the remainder of the defect, an additional skin graft is obtained from the supraclavicular area. If thinner skin is required for grafting of defects of the eyelids or nasal sidewall, postauricular skin is wellsuited for these purposes.
Case illustrations Skin grafting When local flap reconstruction is unfeasible or is not indicated because of the size or location of the defect, we use full-thickness skin grafts (FTSG) for reconstruction. Occasionally, a combination of a local skin flap and FTSG is necessary to repair large defects following excision of AJMH and LM (Fig. 6). In such instances, a transposition flap is designed as large as possible while still allowing primary closure of the donor wound. The SCD that results from transposing the flap to the recipient site is removed and used as a FTSG to repair the portion of the defect
The patient in Fig. 6A had a LM lesion on her left cheek and underwent two stages of the square procedure. The original margins are marked by the sutures that comprise the smaller, pentagonal-shaped sutured wound, and an area positive for AJMH was noted along the posteroinferior border. Another margin was obtained, and found to be free of AJMH; the margins now appear as sutured wounds. The two linear wounds at the posteroinferior border of the sutured area reflect the second stage of the square procedure. A transposition flap was planned for reconstruction of the defect (Fig. 6B). Skin from the lower cheek is marked for transposition into the
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Fig. 7. (A, B) Patient following two stages of the square procedure for a lesion on the left upper lip and cheek. (C) Intraoperative view, a laterally-based transposition cheek flap and two FTSGs were used to reconstruct the defect. (D, E) One-year postoperative appearance.
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evaluated by a dermatopathologist and found to be free of AJMH before resection of the primary lesion with concomitant reconstruction. A lateral-based, cheek advancement flap was used for a portion of the repair (Fig. 7C). A FTSG that was taken from the supraclavicular area was used to reconstruct the remaining lip and a small portion lateral to the left oral commissure. The 12-month postoperative appearance is shown in Figs. 7D and 7E.
Acknowledgments The authors thank Dr. Timothy Johnson for his invaluable editorial assistance in the preparation of this chapter.
References
Fig. 7 (continued ).
defect. The primary lesion was resected and the resultant defect was reconstructed during the same procedure. Note that the original, AJMH-positive margin is included with the primary specimen (see Fig. 6B). The size of the defect did not allow complete closure of the wound without excessive wound closure tension, so a triangular-shaped, full thickness skin graft was used to cover an area adjacent to the lower eyelid (Fig. 6C). The source of the FTSG was the SCD excised during transfer of the transposition flap. Fig. 6D shows the reconstructed cheek defect 6 months following the initial reconstruction. The patient shown in Fig. 7A and 7B had a LM lesion on the left upper lip. The square procedure was performed and the margins have been cleared of LM/AJMH. At the time that this patient was treated, our practice was to allow the strip wounds created by the square procedure to granulate and remain open while the margins were being read. We currently suture closed the strip wounds for greater patient comfort and enhanced cosmesis before definitive resection of the LM and reconstruction (see Fig. 3). An area positive for AJMH was noted laterally in the melolabial sulcus, and this area was re-resected. Not seen (see Fig. 7A, B) is the strip wound along the vermilion border inferior to the lesion on the upper lip. This margin was also
[1] Balch CM, Soong SJ, Greshenwald JE, et al. Prognostic factors analysis of 17,600 melanoma patients: validation of the American Joint Committee on Cancer melanoma staging system. J Clin Oncol 2001;19(16): 3622 – 44. [2] Greshenwald JE, Thompson W, Mansfield PH, et al. Multi-institutional melanoma lymphatic mapping experience: the prognostic value of sentinel lymph node status in 612 stage 1 or 2 melanoma patients. J Clin Oncol 1999;17:976 – 83. [3] Greenlee RT, Murray T, Bolden S, et al. Cancer statistics, 2000. CA Cancer J Clin 2000;50:7 – 33. [4] Rigel DS, Carucci JA. Malignant melanoma: prevention, early detection, and treatment in the 21st century. CA Cancer J Clin 2000;50:215 – 36. [5] Jemal A, Thun MJ, et al. Cancer statistics, 2002. CA Cancer J Clin 2002;52:23 – 47. [6] Rigel DS, Friedman RJ, Kopf AW. The incidence of malignant melanoma in the United States: issues as we approach the 21st century. J Am Acad Dermatol 1996; 34:839 – 47. [7] Newell GR, Sider JG, Bergfeld L, et al. Incidence of cutaneous melanoma in the United States by histology with special reference to the face. Cancer Res 1988; 48:5036 – 41. [8] Cohen LM. Lentigo maligna and lentigo maligna melanoma. J Am Acad Dermatol 1995;33:923 – 36. [9] Clark Jr WH, Elder DE, Guerry IV D, et al. Model predicting survival in stage I melanoma based on tumor progression. J Natl Cancer Inst 1989;81: 1893 – 904. [10] Johnson TM, Dolan OM, Hamilton TA, et al. Clinical and histologic trends of melanoma. J Am Acad Dermatol 1998;38:681 – 6. [11] Langford FPJ, Fisher SR, Molter DW, et al. Lentigo maligna melanoma of the head and neck. Laryngoscope 1993;103:520 – 4.
K.W. Anderson, S.R. Baker / Facial Plast Surg Clin N Am 11 (2003) 93–105 [12] National Institutes of Health Consensus Development Panel on Early Melanoma. Diagnosis and treatment of early melanoma. JAMA 1992;268:1314 – 9. [13] Johnson TM, Smith JW, Nelson BR, et al. Current therapy for cutaneous melanoma. J Am Acad Dermatol 1995;32:689 – 707. [14] Weinstock MA, Sober AJ. The risk of progression of lentigo maligna to lentigo maligna melanoma. Br J Dermatol 1987;116:303 – 10. [15] Zitelli JA, Brown CD, Hanusa BH. Surgical margins for excision of primary cutaneous melanoma. J Am Acad Dermatol 1993;37:422 – 9. [16] Cohen LM, McCall MW, Hodge SJ, et al. Successful treatment of lentigo maligna and lentigo maligna melanoma with Mohs micrographic surgery aided by rush permanent sections. Cancer 1994;73(12):2964 – 70. [17] Coleman WPI, Davis RS, Reed RJ, et al. Treatment of lentigo maligna and lentigo maligna melanoma. J Dermatol Surg Oncol 1980;6:476 – 9. [18] Dhawan SS, Wolf DJ, Rabinovits HS, et al. Lentigo maligna: the use of rush permanent sections in therapy. Arch Dermatol 1990;126:928 – 30. [19] McLean DI, Peter KK. Apparent progression of lentigo
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maligna to invasive melanoma during treatment with topical azelaic acid. Br J Dermatol 1986;114:685 – 9. Robinson JK. Margin control for lentigo maligna. J Am Acad Dermatol 1994;31:79 – 85. Ryan RF, Krementz ET, Litwin MS. A role for topical 5-fluorouracil therapy in melanoma. J Surg Oncol 1988;38:250 – 6. Zalla MJ, Lim KK, DiCaudo DJ, et al. Mohs micrographic excision of melanoma using immunostains. Dermatol Surg 2000;26:771 – 84. Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:202 – 6. Shafir R, Hiss J, Tsur H, et al. Pitfalls in frozen section diagnosis of malignant melanoma. Cancer 1983;51: 1168 – 70. Zitelli JA, Moy RL, Abell E. The reliability of frozen sections in the evaluation of surgical margins for melanoma. J Am Acad Dermatol 1991;24(1): 102 – 6. Baker SR, Swanson NA. Local flaps in facial reconstruction. St. Louis: Mosby; 1995.
Management of early lentigo maligna and lentigo maligna melanoma of the head and neck Kenneth W. Anderson, MDa, Shan R. Baker, MD, FACSb,* a
Department of Otolaryngology-Head and Neck Surgery, University of Michigan Hospitals, 1500 East Medical Center Drive, TC 1904, Ann Arbor, MI 48109, USA b Department of Otolaryngology-Head and Neck Surgery, Division of Facial Plastic and Reconstructive Surgery, Center for Facial Cosmetic Surgery, University of Michigan Medical Center and Comprehensive Cancer Center, 19900 Haggerty Road, Suite 103, Livonia, MI 48152, USA
As the general public becomes increasingly educated about health matters, melanoma has earned a reputation as a lethal disease to be feared. Although it is less common than squamous cell and basal cell carcinoma, the mortality rate for patients with melanoma is significantly greater. As many as one third of melanomas occur on the head and neck. For this reason, the facial surgeon must be familiar with the disease, especially with regard to management of early lesions. The chance for cure is high if melanoma is detected early and treated appropriately, usually through surgical resection. Advanced melanoma carries a worse prognosis, regardless of treatment. This article reviews the clinical and histopathologic characteristics of melanoma. Atypical junctional melanocytic hyperplasia and its significant role in the surgical management of melanoma of the head and neck is discussed. In addition, the principles of managing the most common melanoma subtypes located on the head and neck, lentigo maligna (LM) and lentigo maligna melanoma (LMM), are discussed. A staged excision technique called the ‘‘square’’ procedure is used for LM and LMM and features 100% peripheral margin control before reconstruction of the defect. Principle methods of reconstruction are reviewed, and two case illustrations are provided [1,2].
Epidemiology Melanoma continues to present a significant public health problem; the number of new cases of melanoma is rising at a rate that is higher than that of any other cancer [3]. In the 1930s, the lifetime risk of an American developing melanoma was 1 in 1500 [4]. Estimates place the lifetime risk for Americans born in the year 2000 at 1 in 75; those born in 2010 will face a lifetime risk of 1 in 50. It has been further estimated that 53,600 cases of invasive melanoma and 34,300 cases of melanoma in situ will be diagnosed this year in the United States [5]. Despite the rising incidence, there has been an increase in the 5-year survival rate [6], which is approximately 80% to 90% compared with about 40% in the 1940s. This increase is attributable to public and health care provider awareness that results in earlier detection of lesions. The effectiveness of surgical excision for primary melanoma has not changed significantly over this same time period. Because of the exponential increase in incidence, the death rate from melanoma continues to climb despite improved survival rates. In 2002, the number of deaths that were attributable to melanoma in the United States was estimated to be 7700, or about one death every hour.
Etiology * Corresponding author. E-mail address: [email protected] (S.R. Baker).
Genetic and environmental factors are involved in melanoma development. The most widely accepted
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predisposing environmental risk factor for the development of melanoma is exposure to ultraviolet light, primarily from sunlight. Excessive lifetime exposure, intermittent exposure, artificial light sources (sunlamps), and a history of blistering or peeling sunburns are associated with an increased risk. Many investigators now believe that intermittent acute exposures are more damaging than cumulative exposure, especially exposures acquired during childhood through young adulthood [7]. Approximately 70% of melanomas are sun-related, with an unknown cause in the other 30%. Several other known risk factors associated with melanoma include the presence of dysplastic nevi, more than 100 normal moles, inability to tan, previous personal or family history of melanoma, and fair skin type, especially in association with blue eyes and blonde or red hair [8].
Recognizing melanoma Roughly one half of melanomas arise in a preexisting nevus, with the remainder arising in previously unaffected, normal-appearing skin. The ABCDs of melanoma may provide clues that a benign nevus has transformed into melanoma. ‘‘A’’ stands for lesional asymmetry; ‘‘B’’ is for border. Lesions with asymmetrical, scalloped, or indistinct borders should raise clinical suspicion. ‘‘C’’ stands for color; lesions that display intensely dark pigment, or shades of red, white, or blue are more closely associated with melanoma. ‘‘D’’ is for diameter; lesions larger than 6 mm in diameter are more concerning.
Histopathophysiology and prognostic variables Every melanoma begins with a proliferation of melanocytes. Initially the proliferating cells appear as nests of atypical melanocytes at the epidermal-dermal junction. The rate and characteristics vary in their progression from a small focal area of neoplastic cancerous melanocytes to a vertically invasive, potentially metastatic melanoma. As these nests of cells proliferate, melanocytes also scatter upward into the epidermis, the so-called ‘pagetoid’ pattern of spread. The melanocytes within the tumor display a uniform, atypical appearance that features nuclear atypia, prominent nucleoli, mitosis, and increased cell size. If confined to the epidermis, the lesion is considered melanoma in situ. A transformation to invasive melanoma occurs when the basement membrane of the epidermal layer is breached as the atypical melanocytes grow down into the dermis. A radial growth
phase was described [9] wherein the atypical cells proliferate in a progressive horizontal centrifugal pattern along the epidermal – dermal junction. This occurs for a variable length of time, depending on the histological pattern of the melanoma. The radial growth phase is followed by the vertical growth phase, during which the atypical melanocytes grow deeper into the dermis. Often this is heralded by ulceration, bleeding, and nodule formation. The mean age at time of diagnosis is 50 years for women and 55 years for men [10]. Patients can and do present at any age, however, often with a history of a slowly evolving change of a precursor lesion over the previous 1 to 5 years. Classically, four subtypes of melanoma are described, and are divided according to histological growth patterns. These subtypes include superficial spreading, nodular, acral lentiginous, and lentigo maligna. Superficial spreading melanoma is the most common histologic subtype and represents 70% of all melanomas. There is a characteristic initial radial growth phase that is followed (after a variable amount of time) by the vertical growth phase with associated ulceration, bleeding, and nodule formation. Nodular melanoma is the second most common type and accounts for 15% of all melanomas. The main feature that separates this lesion from a superficial spreading melanoma is the minimal intraepidermal involvement at the periphery of the tumor. Unlike superficial spreading melanoma, the nodular form may display a short radial growth phase (if any at all) and proceeds to the vertical growth phase earlier in the development of the lesion, with the associated nodule formation, ulceration, and bleeding. Acral lentiginous melanona displays histologic features and clinical behavior that is also similar to the superficial spreading subtype. These melanomas are unique because of the location of the tumor on the palms, soles, nail beds, and oral mucous membranes. They appear most commonly on the plantar surface of the foot and is the most common subtype in the black population. Lentigo maligna melanoma most commonly occurs on the head and neck [7] and represents 10% to 33% of all melanomas in this location [11]. It has several characteristics that distinguish it from the classic superficial spreading subtype that are discussed in detail below. In the past, it was believed that each growth pattern represented a different subtype of melanoma, each with a unique patient profile, pattern and rate of growth and invasion, preponderance for metastasis, and prognosis. Accurate pathologic interpretation of a biopsy specimen is critical to
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determining treatment and prognosis for melanoma. Significant prognosis variables include histologic subtype, depth of invasion, anatomic site, mitotic rate, growth phase (radial vs. vertical), and the presence or absence of ulceration, host inflammatory response, angiolymphatic spread, and a precursor lesion [12]. Tumor thickness is the best predictor and single most important factor in determining prognosis and appropriate management of patients. The status of ulceration has proven to be another highly significant prognostic factor. The histologic subtype of the melanoma was reported to influence prognosis; nodular and acral lentiginous patterns have a worse prognosis than other types. After adjustment for tumor thickness, however, the unfavorable prognostic association disappears [13].
Lentigo maligna melanoma Lentigo maligna melanoma has several characteristics that make it unique. Almost all LMM lesions occur in areas of chronic sun exposure and typically are located on the face; the nose and cheeks are the most common sites. Lentigo maligna is a melanoma in situ and may appear as a light brown macule that develops in chronically sun-damaged skin. Its appearance has been likened to a stain on the skin. LM lesions often have a prolonged radial growth phase, which may last for decades. As such, LM usually develops in older individuals; the average age of diagnosis is approximately 65 years of age and these lesions are uncommon before the age of 50. The classic histologic characteristics of LM lesions include an increased number of atypical basal layer melanocytes with intraepithelial growth that extends along the cutaneous adnexal structures, especially the hair follicles and sweat ducts deeper in the dermis. These findings are seen within a background of solar elastosis and chronic sun-damage changes, as evidenced by atypical junctional melanocytic hyperplasia (AJMH). After a protracted radial growth phase, invasion into the papillary dermis signals the invasive phase and signifies the transformation to LMM. Vertical growth phase progression may be evident clinically by the appearance of one or more nodules within the macular lesion. The fraction of LMs that progress to LMM is unknown, but estimates have placed the lifetime risk of malignant degeneration at 5% to 50% [8,14]. Some investigators believe that transformation from the in situ LM to the invasive LMM will eventually occur in all lesions if the patient lives long enough [8].
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Atypical junctional melanocytic hyperplasia Subtle features distinguish normal background melanocytic upregulation secondary to chronic photo-damage, scarring, or inflammation from atypical junctional melanocytic hyperplasia. The distinction requires a dermatopathologist with extensive expertise and experience, as well as clinical correlation. AJMH is characterized by melanocytic hyperplasia with random varying atypia of single cells at the epidermal – dermal junction with frequent deeper extension down adnexal structures. AJMH may display a significant degree of cytologic atypia, mitotic figures, and areas of continuous, lentiginous proliferations and nests. With increasing degrees of melanocytic atypia, there is a continuous progression of AJMH with slight, moderate, and severe atypia. The terms ‘‘AJMH with severe atypia’’ and ‘‘lentigo maligna’’ can be used interchangeably, as they refer to the identical in situ melanoma lesion. LM lesions display a region of central marked atypia that merges with less prominent AJMH at the periphery of the lesion. Usually, there is no distinct clinical margin to the atypia making the evaluation of the peripheral margins of LM/LMM especially difficult, as the AJMH progresses from marked to moderate to slight atypia. Moreover, an unpredictable subclinical extension of AJMH is predominantly associated with the LM/LMM subtype. The peripheral AJMH extends beyond visible margins and Wood’s lamp margins. It can be further camouflaged on the head and neck by freckles, pigmented actinic keratoses, lentigines (sun spots), nevi, or seborrheic keratoses [15]. Unresected AJMH may recur as LM (in situ melanoma) and less frequently, as invasive melanoma. Although rare, these local recurrences may develop rapidly (less than 1 year) and are associated with an increased rate of metastasis and a worse prognosis (Fig. 1). Thus, accurate interpretation of lesional AJMH/LM is critical when evaluating surgical margins when an LM/ LMM lesion is exercised. With the increasing emphasis on the diagnosis of early melanoma, the distinction between AJMH and upregulation of melanocytes in sun-damaged skin creates special challenges in the management of LM/LMM on the head and neck.
Destructive treatment modalities Although surgical excision has been the traditional treatment for LMM of the head and neck, other treatment modalities exist. These alternative methods, reported for use with LM but not LMM,
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destruction must extend to the base of the adnexal structures in the middle to deep dermis, and sometimes fat, to minimize the chance for local recurrence. Additionally, cryosurgery and laser ablation have the added disadvantage that they may destroy the melanocytes’ ability to make pigment, which will make a local recurrence amelanotic. Such recurrences are obviously difficult to detect early and monitor. Destructive modalities may be useful for smaller lesions in selected patients or areas without adnexal structures, such as oral mucosa; however, surgical excision with meticulous histologic margin control results in the highest cure rate for LM and LMM and is the preferred treatment [8,17,18,20].
Surgical treatment modalities
Fig. 1. The recurrent melanoma with satellitosis shown here developed in the site of an incompletely resected lentigo maligna lesion. The original lesion demonstrated atypical junctional melanocytic hyperplasia with slight atypia to the peripheral margins. Note the scar in the central portion of the melanoma corresponding to the previous resection. Unresected AJMH resulted in a rapidly growing, locally recurrent, invasive lesion 8 months after initial resection. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:20 – 6; with permission.)
The highest chance for cure is realized through total surgical excision of the primary lesion and with total peripheral margin evaluation and control. The current recommendations for surgical margins for lesions not on the head and neck are 0.5 cm for in situ melanoma and 1 to 2 cm for invasive melanoma, depending primarily on tumor thickness and the presence or absence of ulceration. These recommendations, especially for the LM/LMM subtype on the head and neck, however, are usually not adequate because of frequent subclinical extension of AJMH. Studies showed that for LM on the head and neck, the average margin required for clearance was 8.3 mm; margins of 15 mm were required to clear 96% of tumors. For LMM, an average margin of 11.8 mm was necessary for clearance, with fully 26 mm margins required to clear 95% of lesions [22].
Margin control involve the destruction of the superficial lesion using cryosurgery, radiotherapy, electrodesiccation and curettage, laser surgery, topical 5-fluorouracil, and azelaic acid [8,16 – 21]. The local recurrence rates using these techniques are high, and range from 20% to 100% [8,17]; this is largely because of the atypical junctional melanocytes that extend down and around the hair follicles and sweat glands that often are not effectively treated using destructive modalities. Other disadvantages include the lack of a specimen for the dermatopathologist to use to assess peripheral margins and to examine histologically. Thus, there is no way to detect any subclinical peripheral extensions of AJMH. In addition, there is no way to detect an invasive component of the primary lesion [13]. If such treatment modalities are selected, the tissue
The goal of surgery is to excise the lesion completely following a fundamental oncologic principle, tumor clearance first, and defect reconstruction second. The cosmetic and psychological significance of the face, as well as the presence of vital structures make the preservation of normal, uninvolved skin an important issue. A search for accurate and precise margin control led surgeons to explore alternatives to standard surgical excision with wide margins, such as Mohs micrographic surgery with and without immunostaining, and Mohs surgery with rapid permanentsection processing [18 – 22]. Using these approaches, the reported local control rates are in the range of 90% to 99%. These alternatives, all of which stem from basic Mohs surgery technique, may rely on
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frozen section interpretation of margins and require considerable training to achieve proficiency. The frozen sections must be of exceptional quality and examined by an experienced dermatopathologist or Mohs surgeon to accurately interpret melanoma margins. The addition of immunostaining may improve accuracy, although this is a labor-intensive process and the benefit is highly debatable [22]. Permanent formalin-fixed sections are easier to process and interpret and are superior in quality to frozen sections for melanoma [16]. Taking standard, frozen sections for melanoma margins in the operating theater setting is not dependable and is not recommended [23]. Evaluation of surgical margins for AJMH is nearly impossible on standard, frozen sections because of the artifacts that are created during the freezing process [24,25]. Unresected AJMH may eventually present as LM or invasive LMM recurrences. Therefore, every effort should be directed toward complete excision of the primary lesion with all of the peripheral lesional AJMH. Our experience in treating LM/LMM subtype lesions in the 1980s and early 1990s, with standard Mohs and surgical excision using standard bread loaf permanent section processing for ill-defined lesions at the University of Michigan, was associated with an unacceptable recurrence rate. Because of this, we developed a different approach to these lesions that is relatively simple, technically easy, and more comfortable for the patient. The procedure is staged; total (100%) peripheral margin evaluation is achieved during each stage. Tumor clearance is attempted at the initial stage, with re-resection of positive areas as required (stages 2, 3, and so forth). Excision of the central lesion with reconstruction of the defect is performed as a final stage, only after all margins have been cleared. This technique, known as the ‘‘square’’ procedure, uses permanent formalin-fixed histologic sections (slides) with theoretical total peripheral margin control.
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edges of the margin are straight, with geometric, sharp-angled corners. Thus, a shape such as a square, rectangle, or diamond is usually marked around the lesion. The geometric configuration with angled corners facilitates tissue processing and precise orientation for total (100%) peripheral margin interpretation. If curvilinear incisions are used around the lesion, complete evaluation of the peripheral margins is possible, but requires additional small steps for tissue processing for total margin control. Local anesthesia is introduced into the skin and subcutaneous tissue along the planned margins. Using a two-bladed scalpel with two to four 1 mm spacers, a peripheral strip of tissue 2 mm to 4 mm wide is excised to the underlying adipose tissue (Fig. 2). The outer blade corresponds to the peripheral margin. This is performed along each of the marked linear margins, using a second single-blade scalpel to cut the peripheral tip corners. A ‘‘square’’ of tissue is removed en bloc from the patient. The tissue square, which contains 100% of the peripheral margin, is tagged with a suture for orientation. The resulting geometrically-shaped, excisional strip wound is sutured closed with a running nonabsorbable suture (Fig. 3). Thus, a relatively small strip of tissue around the periphery of the lesion is excised, and as a result, wound care is minimal. The central island of tissue that contains the lesion is left intact while the margins are assessed. The specimen is pinned to Styrofoam to prevent rolling of the edges, and is sent for histologic processing followed by dermatopathologic evaluation. The specimen is embedded in paraffin and routine vertical sections that contain 100% of the peripheral margins are processed. The specimen is inked and a simple cartoon map is included with the
The square procedure The clinical margin of the lesion is outlined, which may be aided by use of a Wood’s lamp in some cases. The Wood’s lamp (UV-A blacklight) may help to distinguish the subclinical extent of some lesions with visual identification of subclinical pigment. A margin is outlined at 0.5 cm to 1 cm from the clinically-apparent borders of the lesion, with the intent to establish margins that are free of lesional AJMH with the initial surgical procedure. The margin around the lesion is usually marked, such that the
Fig. 2. Use of a two-bladed scalpel with a 2-mm spacer facilitates excision of a thin strip of tissue. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:202 – 6; with permission.)
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Fig. 3. The purpose of the initial stages of the square procedure is to define the lesion perimeter. (A) After removal of a strip of tissue around the lesion, the excisional strip wound is sutured closed. (B) The tissue is processed to examine 100% of the peripheral margins. After the peripheral margins have been cleared, the central island of tissue is resected and the wound is reconstructed. (From Anderson KW, Baker SR, Lowe L. Treatment of head and neck melanoma, lentigo maligna subtype. Arch Facial Plast Surg 2001;3:202 – 6; with permission.)
specimen for precise anatomical orientation of the peripheral margins. The dermatopathologist examines the permanent vertical sections and notes any areas that are positive for melanoma or AJMH. Using the cartoon map, any remaining positive areas are reexcised in a similar fashion and sent for permanent vertical sectioning as described earlier. This process is repeated until all of the margins are free of lesion. When the entire peripheral margin is interpreted as being tumor free, the central island of tissue is excised within the defined clear peripheral margins and sent to the laboratory for serial sectioning and histopathologic evaluation for any invasive component. The reconstruction is performed with the confidence that 100% of the margin has been evaluated and interpreted as being free of melanoma.
Lentigo maligna melanoma Nodularity, ulceration, or bleeding from a central area within a LM lesion is suspicious for invasive LMM, and therefore, is excised at the first stage of the square procedure to reduce the risk of further invasion and metastasis. In such cases, the lesion is completely excised with only 1 mm to 2 mm margins for diagnostic purposes and microstaging. Wider margins are subsequently obtained using the square procedure. If the melanoma approaches 1 mm in
Breslow depth, excision of the primary melanoma and sentinel lymph node biopsy is performed at the same time. For lesions that are too large to completely excise in the office, an incisional biopsy of the majority of the lesion and any elevated portions is recommended. Primary closure of this central portion is performed after the sentinel nodes have been found and removed from the patient. The peripheral margins are subsequently cleared for local control using the square procedure if necessary. In histologically equivocal cases, or in patients with severely sun-damaged skin, a random punch biopsy may be taken from the opposite side of the face to help determine normal background melanocytic morphology.
Full square technique If reconstruction of the resected tissue will likely consist of a delayed, full-thickness skin graft, the entire lesion is excised during the first stage. This can be useful in concave facial areas, such as regions of the nose. The peripheral margins are evaluated as described earlier, and the center of the specimen, removed at the initial stage, is serially sectioned and evaluated for any invasive melanoma. The wound is left open to granulate for 1 to 4 weeks to allow formation of a well-vascularized recipient tissue bed that enhances graft survival and creates a more superficial wound that lessens or eliminates contour deformities.
Clinical experience We have used the square procedure since 1994 on hundreds of patients. Follow-up periods of 5 to 10 years are needed to accurately determine the local control rate with the square procedure using a prospective database, but thus far we have experienced only rare recurrences. The square procedure has the benefit of visualization and interpretation of 100% of the peripheral margins, with high-quality, permanent, formalin-fixed histologic analysis. Conservation of tissue is also achieved, which is particularly important when resecting tissue from the face. The technique is a simple, relatively quick, multidisciplinary method that results in high local control rates of LM/ LMM on the head and neck. The facial plastic surgeon can proceed with reconstruction at the time of excision of the primary lesion with the knowledge that the entire peripheral margin has been examined and that the risk of recurrence is minimal.
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Reconstruction Following the square procedure, most patients undergo reconstruction using local skin flaps. Usually transposition or advancement flaps are used and may be combined with full thickness skin grafts for large excisions. Advancement flaps If the defect is small enough, then a simple advancement flap is used. Advancement flaps are created by incisions that allow for a ‘‘sliding’’ movement of the incised tissue. The incisions are usually parallel to the opposite borders of the defect and extend away from the defect for varying lengths. The use of advancement flaps results in primary and secondary tissue movement [26]. Primary movement refers to the pulling, sliding, or pushing of the elevated tissue toward the defect. There is also a small amount of stretching of the flap itself. Secondary movement is the pull of native tissues in a direction opposite to the primary movement. The result is that surrounding skin and soft tissues adjacent to the defect are pulled toward the defect. Secondary movement can sometimes be beneficial because it provides less woundclosure tension and aids in wound closure. Secondary movement is detrimental when the wound is located near a free margin of a facial structure. The resulting pull on structures, such as the lower eyelid, will result in undesirable distortions.
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Advancement flaps always create two standing cutaneous deformities (SCD). These typically require excision by removal of Burow’s triangles, which may also facilitate movement of the flap. Advancement flaps often involve some degree of pivotal movement. The laterally-based cheek advancement flap, for example, relies primarily on the sliding of loose cheek tissue from the lateral to the medial aspect of the face and involves a smaller magnitude of inferior to superior pivotal (rotational) movement. A key advantage of advancement flaps is the ability to excise SCDs anywhere along the entire length of the flap. The preferred location for excising Burow’s triangle is best determined after suturing the leading border of the flap in place. An effort is made to place the incision lines for the Burow’s triangle in the appropriate relaxed skin tension lines (RSTLs) or a cosmetic boundary. For defects of the forehead, a single advancement flap or bilateral advancement flaps work well. The use of the horizontal RSTLs in the forehead and eyebrow region is well suited for camouflaging portions of the scar. The usual ratio of defect length to flap length is 3:1, although if the flap is based on a named artery, a ratio of 4:1 is possible [26]. To facilitate wound closure, greater tissue movement is gained from the temple area of the forehead compared with the more central region. Whenever possible, advancement flaps should be designed to recruit skin from this area. An O-T flap, or ‘‘T-plasty’’, transforms a round or triangular defect into a T-shaped scar. The defect is closed by advancing flaps in opposite directions from
Fig. 4. (A) Illustration of a T-plasty closure following the removal of a circular defect above the left eyebrow. The shaded areas are removed after the primary lesion is resected circular defect. Wedges of tissue are removed from the base of the wound at the perimeter of the circular defect. Superiorly, an M-plasty serves to shorten the vertical scar length. The shaded ‘‘M’’ superiorly, as well as the Burow’s triangles at each end of the horizontal limb of the flaps, are likewise removed. (B) Final appearance after closure of the wound. The horizontal limb of the T is camouflaged just above the eyebrow.
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Fig. 5. (A) Following removal of a circular lesion at the alar base, a triangular subcutaneous island pedicle flap is incised in the melolabial sulcus. The triangular, shaded areas between the circular defect and the planned wedge-shaped cutaneous portion of the flap are excised. (B) The skin flap based on a subcutaneous pedicle is advanced into the defect site with a skin hook. (C) Final appearance after the defect is closed in a V-Y fashion.
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either side of a triangular or circular-shaped wound (Fig. 4). One advantage of this type of repair is that the defect is repaired with two smaller flaps rather than one large flap. The tissue for wound repair is obtained from two separate areas which facilitates donor site closure. The incisions often can be placed in natural lines, creases, or at the junctional border of adjacent esthetic regions. T-plasty works well on the central forehead when the vertical limb can be placed in the midline. Other suitable locations for T-plasty closure include areas just above the eyebrow or the temple area adjacent to the hairline. In such cases, the horizontal limb of the T-plasty is placed along the border of the eyebrow or in the hairline. T-plasty also works well on the upper lip next to the vermilion and on the chin. In this instance, the horizontal portion of the T-plasty may be camouflaged by placing it along the vermilion border or the mental crease, respectively. An island V-to-Y advancement flap is well-suited for repair of medium-sized defects of the upper lip near the alar base. The pedicle of the flap consists of the underlying subcutaneous tissue. Undermining is
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performed around the periphery of the flap and defect to facilitate closure. As the flap is advanced on its subcutaneous pedicle toward the defect, the donor area is closed primarily creating a V to Y configuration of the wound closure line (Fig. 5). The size of the flap should approximate that of the primary defect; an effort is made to place the incision lines parallel to, or in the borders of, adjacent esthetic regions. For upper lip defects near the nasal sill, the lateral limb of the flap usually can be placed in the melolabial sulcus. Another advantage of this flap for defects of the lateral upper lip is that it permits reconstruction of the moustache in men, as the flap uses hair-bearing skin from the upper lip with proper orientation of the facial hair. This flap can also be used successfully for defects of the medial cheek. Transposition flaps Transposition flaps are a common method of repairing defects after the square technique is used on the cheek. Transfer of tissue is accomplished by
Fig. 6. (A) Patient following two stages of the square procedure for a lesion on the cheek. (B) Excision of central island of tissue and transposition flap designed for repair of wound is marked. (C) Intraoperative view of transposition flap following transfer. A FTSG was used to reconstruct a region of the wound near the lower eyelid; the source of the FTSG was the SCD created by the transposition flap. (D) Six-month postoperative appearance.
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Fig. 6 (continued).
moving the flap through an arc about a pivotal point located adjacent to a border of the defect. In essence, tissue is transferred from an area where it is more abundant to an area that requires resurfacing. A variety of design patterns, including the rhombic flap, banner flap, bilobed flap, and bilateral rhomboid flap, is a testament to the versatility of this method of reconstruction. An advantage of transposition flaps is the ability to design flaps with an orientation that results in minimal wound closure tension and maximum scar camouflage [26].
that is not closed by the flap. Additional incisions elsewhere on the head and neck are thus avoided, along with the obligatory donor site scarring and potential morbidity. If the SCD is not sufficient to repair the remainder of the defect, an additional skin graft is obtained from the supraclavicular area. If thinner skin is required for grafting of defects of the eyelids or nasal sidewall, postauricular skin is wellsuited for these purposes.
Case illustrations Skin grafting When local flap reconstruction is unfeasible or is not indicated because of the size or location of the defect, we use full-thickness skin grafts (FTSG) for reconstruction. Occasionally, a combination of a local skin flap and FTSG is necessary to repair large defects following excision of AJMH and LM (Fig. 6). In such instances, a transposition flap is designed as large as possible while still allowing primary closure of the donor wound. The SCD that results from transposing the flap to the recipient site is removed and used as a FTSG to repair the portion of the defect
The patient in Fig. 6A had a LM lesion on her left cheek and underwent two stages of the square procedure. The original margins are marked by the sutures that comprise the smaller, pentagonal-shaped sutured wound, and an area positive for AJMH was noted along the posteroinferior border. Another margin was obtained, and found to be free of AJMH; the margins now appear as sutured wounds. The two linear wounds at the posteroinferior border of the sutured area reflect the second stage of the square procedure. A transposition flap was planned for reconstruction of the defect (Fig. 6B). Skin from the lower cheek is marked for transposition into the
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Fig. 7. (A, B) Patient following two stages of the square procedure for a lesion on the left upper lip and cheek. (C) Intraoperative view, a laterally-based transposition cheek flap and two FTSGs were used to reconstruct the defect. (D, E) One-year postoperative appearance.
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evaluated by a dermatopathologist and found to be free of AJMH before resection of the primary lesion with concomitant reconstruction. A lateral-based, cheek advancement flap was used for a portion of the repair (Fig. 7C). A FTSG that was taken from the supraclavicular area was used to reconstruct the remaining lip and a small portion lateral to the left oral commissure. The 12-month postoperative appearance is shown in Figs. 7D and 7E.
Acknowledgments The authors thank Dr. Timothy Johnson for his invaluable editorial assistance in the preparation of this chapter.
References
Fig. 7 (continued ).
defect. The primary lesion was resected and the resultant defect was reconstructed during the same procedure. Note that the original, AJMH-positive margin is included with the primary specimen (see Fig. 6B). The size of the defect did not allow complete closure of the wound without excessive wound closure tension, so a triangular-shaped, full thickness skin graft was used to cover an area adjacent to the lower eyelid (Fig. 6C). The source of the FTSG was the SCD excised during transfer of the transposition flap. Fig. 6D shows the reconstructed cheek defect 6 months following the initial reconstruction. The patient shown in Fig. 7A and 7B had a LM lesion on the left upper lip. The square procedure was performed and the margins have been cleared of LM/AJMH. At the time that this patient was treated, our practice was to allow the strip wounds created by the square procedure to granulate and remain open while the margins were being read. We currently suture closed the strip wounds for greater patient comfort and enhanced cosmesis before definitive resection of the LM and reconstruction (see Fig. 3). An area positive for AJMH was noted laterally in the melolabial sulcus, and this area was re-resected. Not seen (see Fig. 7A, B) is the strip wound along the vermilion border inferior to the lesion on the upper lip. This margin was also
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