Chapter 26

Plastic Surgery and Skin and Soft Tissue Surgery

Nick Tarola

John H. Moore Jr.

I Plastic Surgery

Plastic surgery as an art and science deals with the reconstruction of body parts altered by trauma, birth defects, or advanced age. It is one of the oldest fields of surgery, having first been described in 700 B.C., in India. In 1818, von Graefe used the term plastic in his monograph on nasal reconstruction; and throughout the years since then, this term has been associated with surgery that is concerned with form and function. An understanding of the skin layers and of suturing techniques is essential to plastic surgery (see Chapter 2).

A

Skin or the integumentary system , is the largest organ in the body. Three properties of skin are essential for understanding reconstruction—elasticity, extensibility, and resilience.

Elasticity keeps skin in constant tension, owing to underlying collagen fibers. The function of elasticity becomes apparent when facial wrinkles form in its absence.

Extensibility refers to the skin's ability to stretch, which can be seen on abdominal skin during pregnancy.

Resilience is noted by the skin's resistance to infection and puncture.

B

Skin grafts are segments of epidermis and dermis that have been detached from their native blood supply to be transplanted to another area of the body. A skin graft may be an autograft (i.e., from the same person), an allograft (i.e., from a genetically dissimilar individual of the same species, usually a cadaver), or a xenograft (i.e., from a different species, usually pigs) (see Chapter 24, I B 1). Cultured skin can be grown from human epidermal cells; this skin is most useful for extensively burned patients because more surface area can be covered; however, the cultured skin tends to be very thin.

Types. Skin grafts are classified according to thickness.

Split-thickness skin grafts contain the epidermis and a portion of the dermis. They are further divided into thin, medium, and thick, based on the amount of dermis included in the graft (0.010– 0.025 inch). The abdomen, buttocks, and thighs are common donor sites.

Advantages of split -thickness skin grafts include:

A large supply of donor areas

Ease of harvesting

Availability of donor site for reuse in 10–14 days

Decreased primary contracture

Coverage of large surface areas

Ability to be stored for later use

Disadvantages of split -thickness skin grafts include:

Cosmetic inferiority to full -thickness skin grafts

Decreased durability

Hyperpigmentation

Increased secondary contracture

Full -thickness skin grafts contain the epidermis and the full thickness of dermis without subcutaneous fat. They are most useful for covering defects on the face or hand that are not

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amenable to coverage with a skin flap (see I C). A good match of skin color can be obtained from donor sites in the postauricular or supraclavicular areas. Preauricular grafts provide the best color match for the face. The forearm and groin can also serve as donor sites for defects below the clavicle.

Advantages of full -thickness skin grafts include:

Cosmetic superiority to split -thickness skin grafts

Decreased secondary contractures (grafts may be cut as required to fill the defect)

Increased durability

Disadvantages of full -thickness skin grafts include:

Limited donor sites

Increased primary contracture

Composite grafts are those that are formed of multiple tissues (e.g., a fingertip containing skin, subcutaneous fat, and bone or a segment of ear containing skin and cartilage). These grafts may be effective in young patients or in situations where the distal portion of the graft is less than 1 cm from the blood supply.

Grafting procedures

Split-thickness skin grafts are best obtained with specifically designed instruments rather than being taken freehand.

Methods of obtaining the graft include the following:

Knives , such as the Humby or Weck, are fitted with an adjustable roller or gauge to determine thickness. The knife is slowly advanced as cutting proceeds in a back -and - forth direction.

The drum (Reese) dermatome fixes the epidermis to the drum with glue, which allows the graft to be cut as the drum is rolled back. The cut grafts have a uniform thickness.

The electrical dermatome, such as the Brown or Padgett, has a rapidly oscillating knife and a gauge to adjust depth. Long strips of skin can be removed with this instrument.

Care of the donor site following the cessation of capillary oozing will aid in re-epithelialization.

Meshed, nonadherent gauze allows the scab to be incorporated into the dressing. In 2 days, the dressing is dry; the covering, with the incorporated scab, falls from the wound in 2 weeks.

Semipermeable membranes trap leukocyte-rich fluid to form an artificial blister, which hastens epithelialization. Patients note diminished pain at the donor site.

Care of the recipient (grafted) site (see I B 3)

Hemostasis is necessary to ensure adequate tissue contact.

When excessive wound drainage or potential infection may be a problem, the graft can be cut and a meshing device can be used to ensure adequate drainage. This technique is also useful for expanding the surface area of a graft. Epithelialization quickly occurs in the meshed interstices following graft “take.” Meshing of the graft can sometimes lead to a “cobblestone” effect in the final result of the graft. This effect can be minimized with a pressure garment (e.g., Ace bandage, Jobst garment) in the first few months after the grafting procedure.

The graft may be fixed to the recipient site by sutures or tapes. An external fixation with a “tie-over bolus” dressing (i.e., a large dressing made of gauze or cotton) may be required in areas where immobilization is difficult or where shear forces are expected. The open method, in which the graft is left exposed, may be useful for large surface areas in burn patients; daily inspection for infection is important.

Full -thickness skin grafts

Method of obtaining the graft. The grafts are “harvested” with a freehand technique using a no. 10 or no. 15 knife blade. A portion of subcutaneous fat is also harvested and must be excised carefully before grafting.

Care of the donor site involves primary skin closure in most instances. Split -thickness skin grafts may be necessary in some cases.

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Care of the recipient site is similar to care in split -thickness skin grafts. Tie-over bolus dressings are frequently used.

Survival of skin grafts

Vascular recipient beds are necessary to provide nourishment for the transplant tissues.

Imbibition of plasma supports survival during the first 48 hours. Fibrin is laid down and helps to hold the graft in place.

Inosculation (vascular budding) occurs, and the graft is usually supported by a true circulation by the fourth to seventh day. Generally, a graft begins to turn pink at this time. Lymphatic connections are formed by the fifth day.

Contact of the skin graft is essential for inosculation to take place. Factors that can lead to loss of contact include:

Tension on the graft

Fluid (e.g., blood, serum, or pus) underneath the graft

Movement between the graft and its bed

Preparation of wound to be grafted

Bone denuded of periosteum, cartilage denuded of perichondrium, and exposed tendon do not support skin grafts; these areas require a flap procedure.

Infected wounds do not support skin grafts. The critical bacterial concentration appears to

be 10 5 organisms per gram of tissue, and quantitative bacterial counts are useful when determining a wound's suitability for grafting. Mechanical debridement with a scalpel and scissors is necessary to remove necrotic tissue. Frequent dressing changes with saline or dilute (0.1 strength) Dakin's solution (i.e., sodium hypochlorite) are also quite effective in debriding wounds. Once there is no further necrotic material in the wound, the use of a biologic dressing (i.e., an allograft or xenograft) helps to reduce the bacterial count.

C

Flaps are segments of skin and subcutaneous tissues that are moved from one part of the body to another, either retaining or transplanting their vascular supply, which is via a segmental artery through a perforating artery to a cutaneous artery supplying the dermal–subdermal plexus. Because of their intrinsic blood supply, flaps are useful for healing and for covering defects that require padding.

Types (Fig. 26 -1)

Skin flaps

Random flaps receive their blood supply from the dermal–subdermal plexus. These flaps lack an anatomically recognized arterial and venous system. Examples include:

Z -plasty (Fig. 26 -2)

V -Y advancement flaps

Rotation flaps (Fig. 26 -3)

Transposition flaps (Fig. 26 -4)

Axial flaps have a direct cutaneous artery and vein supplying their subdermal plexus. Therefore, the blood supply is more reliable than with random flaps, and flaps of greater length may be obtained. Axial flaps may be detached as free microvascular flaps and transplanted to other areas of the body, provided that the vessels are large enough. Examples of axial flaps include:

Forehead flaps

Groin flaps

Deltopectoral flaps

Muscle flaps provide increased blood supply to an area. Generally, they are used to cover exposed bone and are usually skin grafted. When the overlying skin and subcutaneous tissue are included,

they are called myocutaneous (musculocutaneous) flaps.

The blood supply is predictable, and the flaps can be outlined anatomically. The flaps contain muscle with a named artery, which must be identified and preserved (Fig. 26 -5).

Muscle flaps have been most useful in reconstruction of the lower extremity and in areas of poor vascularity. Myocutaneous flaps have been useful for reconstruction of tissue that has been injured by radiation.

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FIGURE 26-1 Types of flaps. (Adapted from

Daniel RK, Kerrigan CL. Principles and physiology of skin flap surgery. In: McCarthy JG, ed. Plastic Surgery. Vol. 1. Philadelphia: WB Saunders; 1990:293.

)

FIGURE 26-2 Classic 60-degree angle Z-plasty.

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FIGURE 26-3 A: Technique for rotation of flap. B: Rotation of a myocutaneous flap used for reconstruction of posterior thigh defect with tensor fascia lata flap.

Fasciocutaneous flaps involve the transfer of skin, subcutaneous tissue, and the underlying fascia with an anatomically distinct artery. Because there is no mobilization of underlying muscle, there is less functional debilitation. The donor site must be skin grafted, and these flaps are cosmetically inferior to muscle flaps.

Free flaps (free tissue transfer) are those in which the native blood supply is completely severed, with transplantation of the flap to a separate body area. They can be muscle, myocutaneous, fasciocutaneous, or axial flaps. They can be used to provide function (free neurotized muscle transfer for correction of facial nerve palsy). Revascularization is accomplished by microvascular anastomosis.

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FIGURE 26-5 A: Arterial blood supply in musculocutaneous flaps. B: The five patterns of vascular anatomy of muscle. (Adapted from

Mathes SJ, Nahai F. Classification of the vascular anatomy of the muscles: experimental and clinical correlation. Plast Reconstr Surg. 1981;67:177.

)

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Uses of flaps include:

Wound closure in areas of poor vascularity (e.g., wounds overlying bare bone, cartilage, nerves, or tendons; radiation -injured tissue)

Facial reconstruction (e.g., the nose or lips)

Areas over bone where padding is needed (e.g., the ischial tuberosity in a patient with pressure sores)

Vascular patency may be assessed by color, temperature, Doppler flowmetry, fluoroscanning, and laser Doppler.

D Reconstructive breast surgery

Techniques are available for treatment of micromastia (small breasts), macromastia (oversized breasts), and gynecomastia and for reconstruction following mastectomy. Because the breast is frequently viewed as a symbol of femininity, there is much emotional overlay in this type of surgery. Careful planning and realistic goals are necessary for patient satisfaction.

Micromastia is present when a patient feels that she lacks development of one or both breasts.

Treatment is by augmentation with a prosthetic implant that can be placed either subglandularly (between the breast and the pectoralis major muscle) or submuscularly (underneath the pectoralis major muscle). The fill material for the prosthetic implant is either intraoperatively injected normal saline or factory -filled silicone. Silicone implants have the advantage of a more natural feel and shape. However, concerns about the potential health risks associated with silicone implants prompted the Food and Drug Administration (FDA) to ban their use in 1992 except in women who have undergone mastectomies or who are part of research studies. On October 16, 2003, an FDA advisory panel recommended that the government approve the use of silicone implants under certain conditions. On January 7, 2004, the FDA rejected the panel's recommendations pending further investigation. Studies by the Mayo Clinic, Harvard Medical School, and the National Academy of Sciences' Institute of Medicine panel found no evidence that leaked silicone from implants causes systemic disease.

Complications, although rare, include infections and hematoma formation. A capsular contracture may form around the implant, which can lead to asymmetry and discomfort. This condition may require a subsequent surgical scar release and is more common when the implant is in the subglandular position.

Explantations, or removal of implants , are becoming increasingly common. Rupture of the silicone gel implant is difficult to diagnose on mammograms, and either ultrasound or magnetic resonance imaging (MRI) is a better option. Frequently, there is no change in the breast of a woman with a ruptured silicone gel implant. If a saline implant ruptures, it generally deflates in a matter of days, making the diagnosis quite easy.

Macromastia is present when the patient feels that she has abnormally large breasts. Frequently, macromastia can be debilitating because of neck and back pain.

Treatment. Various techniques have been described. All involve resecting breast tissue and the inferior breast skin, transposition of the nipple–areolar complex superiorly, and closure of the resultant flap defects. All resected specimens should be examined histologically because occult carcinoma may be present, although rarely is.

Complications include hematoma formation, infection, change in nipple sensation, and necrosis.

Mammary ptosis , or drooping of the breast, is present when the nipple has extended below the inframammary fold. The breast skin envelope is larger than the underlying breast parenchyma. This condition usually occurs after significant weight loss, and it can occur after childbirth.

Treatment involves skin excision similar to breast reduction incisions; however, very little or no breast tissue is removed.

commonly used in breast reconstruction after a mastectomy.

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Free flaps are occasionally indicated. The most common types are the free TRAM and free gluteus maximus myocutaneous flaps for breast reconstruction.

Nipple–areola reconstruction is usually done as a second stage. The nipple is reconstructed most commonly with local flaps and a skin graft to reconstruct the areola. If necessary, the nipple–areola complex can be tattooed to increase pigmentation.

Occasionally, a mastopexy or reduction mammoplasty is necessary for the opposite breast to achieve symmetry.

Postoperative pain relief

Regional anesthesia includes peripheral nerve blocks, local wound infiltration, and epidural and spinal analgesia. Advantages of these types of anesthesia are reduced rates of blood loss, deep venous thrombosis (DVT), and adverse effects of general anesthesia as well as improved pain control. The pain pump, commonly used after breast reconstruction, breast augmentation, and abdominoplasty (procedures where there is a potential space) is a nonelectrical device that continuously delivers pain medication via very small catheters placed in the surgical site at the end of surgery. Commonly used medications are bupivacaine and lidocaine. The device delivers local anesthetic for approximately 48–72 hours, at which time the catheters can be removed by the patient at home.

Patient -controlled analgesia (PCA) allows the patient to self-administer narcotics via an infusion pump of which the dose, dose interval, and infusion rate are preset by the physician. The pump helps to provide the patient with optimal pain relief. The patient has around -the-clock access to narcotics that can be delivered the moment she experiences pain or prior to expected activity. This tends to decrease the apprehension that patients often feel postoperatively about delays in medication administration. Prior to discharge from the hospital, the patient is weaned from the PCA and is given oral pain medication.

E Reconstruction of congenital anomalies

(see Chapter 29)

Congenital anomalies may result from genetic or environmental factors. In most cases, an initiating environmental factor acts on a genetically predisposed individual. The inheritance risk for most anomalies remains low. The repair and reconstruction of many congenital anomalies do not fall within the scope of plastic surgery; examples include the gastrointestinal anomalies discussed in Chapter 29 .

Maxillofacial deformities can be reconstructed by craniofacial surgery.

Soft tissue and bony abnormalities can be reconstructed by a specialized team approach. Examples include:

Hypertelorism

Orbital dystopia

Treacher Collins syndrome

Facial clefts

Crouzon's disease

Apert's syndrome

Cleft lip may be unilateral, bilateral, or incomplete. It is seen in 1 in 1000 births and is more common in Asian children and male children. It is less common in blacks. Reconstruction is generally performed at approximately 3 months of age as determined by the “rule of tens”: 10 lb, 10 weeks of age, and 10 g of hemoglobin. Some surgeons prefer to operate in the neonatal period.

Cleft palate may occur as a defect in the primary or secondary palate or both. It occurs in 0.5 in 1000 births.

Reconstruction is performed before 2 years of age to aid in normal speech development. It commonly involves local flap advancement.

Secondary bone grafting is indicated before permanent teeth erupt if maxillary discontinuity exists.

Early attention to nutrition is important, because sucking is impaired.

F

Facial trauma frequently accompanies other major trauma. After ensuring adequate ventilation and circulation, attention should be directed initially to areas where trauma is more life threatening

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(i.e., the chest and abdomen) (see Chapter 21 I). Once the patient is stabilized, the facial structures can be examined systematically.

Soft tissue

Lacerations of the face bleed readily because of its rich blood supply. Bleeding is controlled by direct pressure and never by “blind” clamping. Control in the operating room may be necessary.

Lacerations may involve deeper structures, such as the facial nerve and parotid duct.

Most lacerations can be repaired by primary closure, following thorough debridement of all devitalized tissue.

Blunt trauma may result in contusions or associated fractures.

Many injuries of this type can be diagnosed initially by inspection; facial asymmetry, if present, should be noted.

Dental malocclusion may signify a mandibular or maxillary fracture.

Instability of the upper jaw may signify a maxillary fracture or midface fracture.

Pain on palpation at the nose, depression, or asymmetry may signify a nasal fracture.

Diplopia, malar deformity, enophthalmos, or hypoesthesia of the cheek may signify an orbital blow-out fracture.

Complete radiologic examination is essential. Operative stabilization is usually required.

FIGURE 26-7 A–C: Vaginal reconstruction with bilateral gracilis myocutaneous flap. D–E: Vaginal reconstruction with bilateral gracilis myocutaneous flap.

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Laser treatments to facial areas (most commonly, CO2 and erbium lasers) are used to treat photoaging of the skin. Other lasers are useful for treating spider veins, benign skin discoloration, and hair removal.

the more common lesions are discussed in this chapter. P.493

Common warts (verrucae vulgaris) occur most frequently in the second decade of life and may be transmitted by direct or indirect contact.

Etiology. They are caused by a member of the papovavirus family, which invades the stratum spinosum epidermidis, causing papillomatosis.

Clinical presentation. The fingers are the most common location. The lesions have a characteristic rough and elevated surface and can become tender.

Treatment involves minimal destruction of normal tissue. In many cases, the warts resolve spontaneously. Problematic lesions can be treated by:

Curettage and electrodesiccation

Freezing with liquid nitrogen

Chemotherapy with caustic agents

Cysts are fluid -filled cavities in the subcutaneous tissues; they may resemble solid tumors.

Epidermal inclusion cysts develop when epidermal cells are trapped in the subcutaneous tissue. Desquamation leads to the creation of a cavity. Excision is curative.

Sebaceous cysts result from blockage of a sweat gland, which causes the accumulation of sebum and the creation of a cyst. Excision is curative and prevents a recurrence. If infection is present, the cyst should be incised and drained before excision.

Dermoid cysts are congenital lesions that may occur later in life. If they occur in the midline (glabellar, nasal), a computed tomography (CT) scan is indicated because there may be intracranial communication. Treatment is by excision.

Ganglia can occur in areas of weakened retinaculum, with outpouching of underlying synovial structures. They occur most commonly on the hands and feet in areas subjected to trauma or inflammation. Excision is curative, but there can be recurrences, which are probably caused by inadequate resection of the ganglion's stalk and base.

Vascular birthmarks are frequently disturbing to the patient and family because they are cosmetically deforming. They are classified on the basis of their clinical and cellular characteristics.

Hemangiomas (strawberry marks) are characterized by increased number of mast cells during the proliferative phase and rapid postnatal growth. These elevated, red, soft, compressible lesions grow rapidly during the first year of life and are most commonly located on the head and neck area and extremities. Spontaneous regression is characteristic. Surgery or steroid therapy is indicated for lesions causing functional impairment (e.g., to the eyes, ears, throat). Rarely, platelet consumption occurs. Hemorrhage is uncommon, and there is usually minimal residual scarring.

Vascular malformations grow at the same rate as the patient; thus, they may not be obvious at birth. They have a normal number of mast cells and may be divided according to the predominant vascular tissue: capillary, venous, lymphatic.

Capillary malformations (capillary hemangioma, port -wine stains) are found on the face, chest, and extremities. They may be associated with Sturge -Weber and Klippel -Trenaunay - Weber syndromes. There is dilatation of the capillaries in the subpapillary, dermal, or subdermal layer. If the tumor is small, excision is curative. Treatment of larger lesions requires careful planning for optimal results. The laser has recently proved to be helpful in treatment.

Venous malformations (cavernous hemangiomas) involve a matrix of mature vessels in the subcutaneous tissues; frequently, they involve deeper structures, including muscle. These lesions may sequester platelets. After careful preoperative planning, treatment involves wide excision with attention to the involved structures. Occasionally, a direct sclerosant injection may be helpful.

Lymphatic malformations (lymphangioma, cystic hygroma) commonly cause hypertrophy of involved soft tissues. Surgical treatment is excision, and seroma is a common complication.

Arteriovenous malformations frequently remain stable in size and then expand. Treatment is by surgical excision.

Vascular tumors are frequently benign; they may cause concern because of their prominence.

Pyogenic granulomas are papular lesions that are commonly located on the face, chest, and fingers; the lesions develop rapidly and then stop enlarging after variable periods of growth. They tend to bleed freely. Surgical excision is usually curative.

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Spider nevi (telangiectasias) occur in all age groups and are commonly located on the face, chest, and extremities. They may arise during pregnancy and with cirrhosis. The lesion consists of a central arteriole with vessels resembling venules that radiate from the center. They rarely bleed, and treatment (i.e., laser therapy, electrodesiccation, or cryotherapy) is undertaken primarily for cosmetic reasons.

Glomus tumors, which are extremely painful, are located most frequently in the nail beds. Treatment is by excision.

Lipomas (fat tumors) can be found in any area of the body where fat is normally found, but they are most common on the neck, shoulders, back, and thighs. Malignant transformation is uncommon, and excision is curative.

Nerve tumors (see Chapter 18, IV F 1, 3) come in two varieties.

Neurilemomas arise from the Schwann cell sheath. They do not cause much pain, and they are treated by excision.

Neurofibromas involve masses of nerve and fibrous tissue and are related to von Recklinghausen's disease. They may undergo malignant degeneration.

Seborrheic keratosis is a light - to dark -brown raised papular lesion, which must be differentiated from malignant skin lesions. Treatment is by biopsy followed by curettage and electrodesiccation.

Keloids are abnormal accumulations of fibrous tissue, which extend above and beyond an area that was previously traumatized (as opposed to hypertrophic scars that remain within those confines). They occur more commonly in blacks. Treatment is by excision and pressure. Occasionally, adjuvant corticosteroid therapy is necessary.

Hidradenitis suppurativa may be confused with a tumor, but it is an infection of the apocrine sweat glands and subcutaneous tissue that occurs most frequently in the axilla or groin. Treatment involves controlling the infection with antibiotics and (if indicated) incision and drainage, followed by excision with either primary closure or a split -thickness skin graft.

C

Premalignant skin lesions are benign lesions with a high likelihood of progressing to invasive squamous cell carcinoma.

Actinic keratosis is a rough, scaly epidermal lesion that occurs in areas of the body subjected to chronic sun exposure.

It may appear in the third or fourth decade of life, and approximately 10%–20% of the lesions undergo malignant transformation.

If biopsy proves the lesion to be benign, it is treated by excision or cryotherapy. Topical chemotherapy with 5-fluorouracil has been useful in patients with many keratoses.

Bowen's disease is intraepidermal squamous cell carcinoma or carcinoma in situ of the skin. It appears as a well-defined, erythematous plaque covered by an adherent scaly yellow crust.

There are no lymphatics in the layer affected, and there is no potential for metastasis.

Bowen's disease occurs mainly in the fourth to sixth decade of life, and ingestion of arsenic and viruses have been implicated as etiologic agents. Treatment is similar to that for actinic keratosis.

Keratoacanthoma is a locally destructive skin lesion that is found most commonly on the head, neck, and upper extremities.

Rapid progression of the tumor occurs within 2–8 weeks, followed by spontaneous resolution.

Treatment is by excision and biopsy of the lesion; squamous cell carcinoma is found in approximately one quarter of the lesions biopsied.

D Nevi (moles)

Overview

Nevi are pigmented lesions of the skin that frequently concern the patient because of the fear of malignancy. Because the average white man has 15–20 nevi, total excision is unreasonable.

Clinical diagnosis is important, because malignant transformation can occur. In general, however, malignant transformation is rare in children. Also, well-circumscribed lesions and lesions with a uniform color rarely progress to malignancy.

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Suspicious -looking lesions should be biopsied by excision with a margin of normal skin.

Benign pigmented lesions

Junctional nevi are dark, flat, smooth lesions, which range generally from 1–2 cm in diameter. They are occasionally hairy and develop from the basal layer of epidermis. Nevi that are located on the palms and soles are usually junctional. They can develop into malignant melanoma, but this rarely

occurs before puberty.

Compound nevi are brown-to -black, well-circumscribed lesions that are usually less than 1 cm in diameter. They may be elevated and are frequently hairy, arising from the epidermal–dermal interface and from within the dermis. Malignant transformation is rare.

Intradermal nevi are light -colored, well-circumscribed lesions less than 1 cm in diameter. Hairs are usually present, and the cell distribution occurs in the dermis. Malignant transformation is rare.

Giant pigmented nevi

These brown-to -black, hairy lesions have an irregular nodular surface. They frequently involve

more than 1 ft2 of body surface and arise from the dermis and junctional areas. The lesions are frequently described, in terms of distribution, as “bathing trunk,” “vest,” “sleeve,” or “stocking.”

Malignant degeneration has been estimated at approximately 10%.

Excision with a margin of normal tissue is indicated, either in stages or with flap reconstruction.

Blue nevi are smooth, hairless lesions measuring less than 1 cm in diameter. They arise in the dermis, and malignant degeneration is rare.

Spitz nevi (benign juvenile melanomas) are smooth, round, pink -to -black lesions measuring 1–2 cm in diameter. They have increased cellularity and occur in nests within the upper dermis. Malignant degeneration is rare.

Nevi must be distinguished from freckles (ephelides). These pigmented lesions occur in the basal and upper dermis and have no malignant potential.

Treatment

Treatment is indicated for junctional and giant pigmented nevi because of their malignant potential.

Indications for excision of any pigmented lesion include:

Changes in color, size, shape, or consistency

Pain

Satellite nodules

Regional adenopathy

Except for large lesions, excisional biopsy, with a margin of normal skin, should be performed. Further therapy may be indicated, depending on the histologic diagnosis and location of the lesion.

For large lesions, a full -thickness wedge biopsy, including a small area of normal skin, should be taken.

E

Malignant melanoma (see Chapter 19, X B ) is a melanoblastic tumor that may develop in the skin or eye.

Epidemiology. The incidence is approximately 13 new cases per 100,000 population a year, representing

an increase of 50% in the past decade. The tumor occurs most commonly in the fifth decade of life, and the incidence is approximately equal in men and women.

Etiology. Exposure to sunlight appears to be an initiating event in the development of melanoma, and fairskinned white people with frequent direct (overhead) exposure to the sun are most often affected.

Detection of melanoma is determined by changes in the color, size, or shape of a nevus.

Men are most frequently affected on the back, chest, and upper extremities.

Women are most frequently affected on the back, lower extremities, and upper extremities.

Classification of melanomas is based on their gross and histologic appearance.

Superficial spreading melanoma accounts for 70% of all melanomas. It can be present on any area of the body but is found most frequently on the back and legs. The median age at

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diagnosis is the fifth decade. The tumor has irregular borders with a varied color pattern. Cell distribution is in the upper dermis with lateral junctional spread. Generally, the prognosis is good.

Nodular melanoma accounts for 15% of melanomas and occurs most commonly in the sixth decade of life. The tumor is blue-black and may be found on any area of the body. Spread is primarily vertical with rapid dermal invasion, and the prognosis is poor.

Acrolentiginous and mucosal melanomas make up 10% of all melanomas. They occur most commonly in the fifth decade of life and are distributed on the mucous membranes, palms, and soles. Irregular borders are common; lesions are generally black but may be amelanotic. Growth occurs slowly in a radial direction; cells are mainly in the upper dermis with occasional deep invasion. The prognosis depends on the depth of invasion and is between that of superficial spreading and nodular melanomas.

Lentigo maligna (melanotic freckle of Hutchinson) is the least common of the melanomas, and it appears most frequently in the seventh decade of life. The lesions are brown-black and contain elevated nodules within a smooth freckle. They occur most frequently on the head, neck, and hand. Growth is slow and in a radial direction, with cells in the upper dermis; vertical extension is infrequent. The prognosis is excellent.

Staging. Classification of the lesion is imperative for optimal treatment. Histologic evaluation with regard to the depth of invasion as well as the type of tumor is important for determining prognosis. To complete the staging, a thorough history and physical examination are necessary, including a complete blood count, 12 - test sequential multiple analysis (SMA-12), urinalysis, and chest radiograph.

Clark's classification assesses the level of invasion and has been adopted by the American Joint Committee for Cancer Staging and End Results.

Level I: The tumor is confined to the epidermis.

Level II: The tumor invades the papillary dermis.

Level III: The tumor fills the papillary dermis but does not invade the reticular dermis.

Level IV: The tumor invades the reticular dermis.

Level V: The tumor invades the subcutaneous fat.

Breslow's method is an additional method that is sometimes used. It involves measuring the depth of invasion precisely in millimeters. However, erroneous estimates of the depth of invasion can occur if ulceration is present.

Patients with Clark's level I, II, or III lesion and with a depth of invasion that is less than 0.76 mm are at low risk for metastasis.

Patients with lesions at level IV or V and with a depth of invasion greater than 1.5 mm are at high risk for distant spread.

Treatment depends on the depth of invasion. Biopsy is by total excision when feasible; otherwise, incisional biopsy is performed. Frozen section is inaccurate in determining the depth of invasion.

Excision. There is debate over the previously accepted 5-cm margin.

For melanoma in situ, 0.5 cm margins are indicated.

For lesions less than 1.0 mm in thickness, a 1-cm margin is generally sufficient.

For lesions 1–4 mm in thickness, 2-cm margins are indicated. The need to excise the underlying fascia is debatable.

For lesions more than 4 mm in thickness, 3-cm margins are indicated.

Lymph node removal

Clinically involved regional lymph nodes with level II, III, IV, or V disease should be resected with an elective lymph node dissection (ELND), which in the case of melanoma entails resection of level I, II, and III lymph nodes.

Sentinal node biopsy is a minimally invasive way of staging clinically occult regional lymph node metastases. Several hours prior to surgery, the area adjacent to the primary lesion is injected with a radiotracer (technetium sulfur colloid) for lymphoscintigraphy in the radiology department for lymph node localization intraoperatively. A visible (isosulfan blue) dye is also injected perioperatively near the lesion. The lymph node(s) in the regional node basin that first takes up these tracers is considered the sentinal node. It is

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excised and examined for disease. The sentinal node biopsy is useful in that it prevents unnecessary ELND and the associated morbidity. If the sentinal node if free of disease, the patient is spared an ELND.

Postoperative morbidity from lymph node resection needs to be considered when lesions involve the face or lower extremities.

Adjuvant therapy is recommended by some authors to prolong the diseasefree interval.

Regional hyperthermic perfusion involves isolating the blood supply of a limb with a pump oxygenator, enabling high doses of chemotherapy to be delivered to the limb at elevated temperatures (40°C) without the side effects of systemic toxicity. The role of this treatment has yet to be clarified.

Chemotherapy with dacarbazine (DTIC), carmustine (BiCNU), and lomustine (CeeNU) has not significantly altered the course of disease.

Immunotherapy is useful for the control of cutaneous metastases, but visceral metastases have not responded to any significant degree.

Radiotherapy is strictly palliative and has been used for brain and bone metastases.

Prognosis is related to the status of the regional lymph nodes. When disease is confined at the primary site, the 5-year survival rate is approximately 80%–90%. If regional lymph nodes are involved, this figure drops to 30%–50%. Patients with distant or visceral metastases usually die within 12 months.

F

Other malignant tumors of the skin commonly occur in exposed areas. Generally, they are low -grade tumors and metastasize late. For this reason, they are highly curable.

Basal cell carcinoma (see Chapter 19, X A ) is the most common skin tumor seen. It is localized and grows slowly, and it generally occurs in the head and neck. It is found most commonly in individuals of northern European descent.

Etiology. Basal cell carcinoma has also been associated with xeroderma pigmentosum, basal cell nevus syndrome, nevus sebaceus, and unstable burn scars. With the advent of radiation therapy, basal cell carcinomas are being seen with increasing frequency in areas of dermatitis.

Clinical presentation. The lesion has pearly, translucent edges, which may become erythematous or pigmented. Frequently, a visible telangiectasia is present. As the lesion grows, it may ulcerate and eventually invade underlying structures. Morphologic types of basal cell cancer include superficial, nodular, pigmented, and morphealike (sclerosing). Metastatic disease is rare.

Treatment involves the complete removal of the tumor to achieve a cure. Biopsy is mandatory to establish a pathologic diagnosis.

Curettage and electrodesiccation result in a 95% cure rate, and the technique is acceptable for lesions less than 2 cm in diameter. The disadvantage is the lack of a specimen for determining the adequacy of resection.

Radiation therapy can be used in areas where tissue preservation is important (e.g., the eyelids). The cure rate is approximately 90%. The disadvantages are that depigmentation and skin atrophy can occur with time.

Excision with primary closure results in a cure rate of approximately 95% and allows inspection of the specimen for adequate margins. If necessary, reconstruction can be performed at the same sitting.

Mohs' micrographic surgery involves tumor mapping to determine the adequacy of resection. Generally, it is most applicable to recurrent tumors, morphealike tumors, and those of the nose or perinasal areas. As cure rates approach 99%, immediate reconstruction can achieve excellent esthetic results.

Cryotherapy is acceptable in certain cases. It has a higher morbidity, and scarring is less predictable than with other techniques.

Topical chemotherapy results in unacceptable cure rates.

Recurrent disease requires wide re-excision.

tendency to metastasize or to invade locally.

Clinical presentation. These tumors usually present as an enlarging mass, which is frequently painless. If they occur in deep locations, such as the retroperitoneum, they are often quite large at the time of diagnosis.

Diagnosis is made on permanent sections of a representative biopsy. MRI is helpful in determining the extent of the tumor. The biopsy should be planned with the future surgical procedure in mind. Excisional biopsy is indicated for lesions less than 3 cm in diameter; otherwise, incisional biopsy is indicated.

Treatment. These tumors are frequently treated inadequately because they have a pseudocapsule, which may lead the surgeon to assume falsely that all of the tumor has been removed. In reality, these tumors extend along tissue planes well beyond their apparent margins.

Wide local excision or amputation is the current accepted treatment. Chemotherapy and postoperative radiotherapy are frequently indicated.

Limb-sparing surgery is indicated when wide local excision can be accomplished without jeopardizing the function of the extremity (i.e., involvement of major nerves or vessels).

Limited surgery with high -dose radiotherapy yields a local recurrence rate similar to that for radical surgery (20%–50%).

The route of metastasis is usually hematogenous , and the lungs are the most frequent site of involvement. Lymphatic spread occurs less often and usually late in the course of the

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disease. Metastatic lesions in the lungs should be resected if the primary tumor is under good control and there is no evidence of other sites of involvement.

Major soft tissue sarcomas

Liposarcoma is the most common of the soft tissue sarcomas in the adult.

Only 1% arise from pre -existing benign lipomas.

Liposarcomas can occur in any area, including the retroperitoneum.

They are treated by wide excision. The tumors are radiosensitive, and radiotherapy may be helpful in locations where wide excision is not possible.

Well -differentiated lesions have a 70% 5-year survival rate, whereas poorly differentiated lesions have only a 20% survival rate at 5 years.

Fibrosarcoma is the second most common soft tissue sarcoma in the adult.

These lesions are usually found in an extremity, where they present as a hard, round mass. They are more common in men than in women and are the most common sarcoma found in black persons.

They are radioresistant, and the treatment is wide excision. Fibrosarcomas are very susceptible to local recurrence and must be treated aggressively at the time of presentation.

Adequately treated fibrosarcomas have a 5-year survival rate of 77%.

Rhabdomyosarcoma arises from skeletal muscle and occurs in both a juvenile and an adult form.

Embryonal rhabdomyosarcoma usually occurs in children younger than 15 years of age.

The head, neck, and genitourinary system are most frequently involved.

This tumor has recently enjoyed a spectacular increase in the 5-year survival rate. The combination of surgery, radiotherapy, and multidrug chemotherapy now achieves a 70% 5-year survival rate for patients with isolated lesions. If metastases are present, the survival rate is lower but is still approximately 40%.

Pleomorphic rhabdomyosarcoma is the histologic type that is usually found in adults.

Wide excision (including amputation, if necessary) is the treatment of choice. Chemotherapy is much less effective in this form of the tumor.

Although lymph node dissections are not done in most cases of sarcoma, they should be done for pleomorphic rhabdomyosarcoma because 25% of patients have regional nodal metastasis.

The 5-year survival rate is 30%.

Kaposi's sarcoma , which has attracted attention recently in connection with acquired immunodeficiency syndrome (AIDS), is a malignant lesion of vascular origin.

Until recently, it was usually seen in the lower extremities of older men. Now, it is often seen in the perianal area in connection with AIDS.

It usually begins as a single bluish -red macule, and gradually, multiple nodules appear and may ulcerate.

A solitary nodule should be excised, and widespread disease should be treated with radiotherapy. Although there is no cure for systemic Kaposi's sarcoma, patients may live for many years.

Lymphangiosarcoma is a peculiar tumor that develops in areas of chronic lymphedema (e.g., in the arm of women with postmastectomy edema, particularly if radiotherapy has also been used). The prognosis is dismal, and there is no effective treatment.

Benign sarcomas

Desmoid tumors are classified as benign fibromatoses that have the capacity to grow to a large size with a high rate of recurrence after excision. They are associated with Gardner's syndrome. They usually affect the shoulder and trunk and may affect the abdominal wall in parous women.

Dermatofibrosarcoma protuberans is a slow -growing nodular tumor with a high recurrence rate after excision. Histologically, it exhibits a “cartwheel” pattern of fibroblasts.

Paraganglioma (chemodectoma, carotid body tumor) presents as a painless mass in the neck overlying the carotid bifurcation. Most tumors are benign. Excision is curative.