Chapter 083. Cancer of the Skin (Part 4)

ManagementThe entire cutaneous surface, including the scalp and mucous membranes, should be examined in each patient. Bright room illumination is important, and a 7x to 10x hand lens is helpful for evaluating variation in pigment pattern. A history of relevant risk factors should be elicited. Any suspicious lesions should be biopsied, evaluated by a specialist, or recorded by chart and/or photography for follow-up. Examination of the lymph nodes and palpation of the abdominal viscera are part of the staging examination for suspected melanoma. The patient should be advised to have other family members screened if either melanoma or clinically...
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Chapter 083. Cancer of the Skin (Part 4) Chapter 083. Cancer of the Skin (Part 4) Management The entire cutaneous surface, including the scalp and mucous membranes,should be examined in each patient. Bright room illumination is important, and a7x to 10x hand lens is helpful for evaluating variation in pigment pattern. Ahistory of relevant risk factors should be elicited. Any suspicious lesions should bebiopsied, evaluated by a specialist, or recorded by chart and/or photography forfollow-up. Examination of the lymph nodes and palpation of the abdominalviscera are part of the staging examination for suspected melanoma. The patientshould be advised to have other family members screened if either melanoma orclinically atypical moles (dysplastic nevi) are present. The detection of earlymelanoma in relatives has been reported. Melanoma prevention is based on protection from the sun. Routine use of abroad spectrum UV-A/UV-B sunblock with sun protection factor ≥15, use ofprotective clothing, and avoiding intense midday ultraviolet exposure should berecommended. The patient should be educated in the clinical features of melanomaand advised to report any growth or other change in a pigmented lesion. Patienteducation brochures are available from the American Cancer Society, theAmerican Academy of Dermatology, the National Cancer Institute, and the SkinCancer Foundation. Self-examination at 6- to 8-week intervals may enhance thelikelihood of detecting change. The importance of routine follow-up visits formelanoma patients and patients with clinically atypical moles (dysplastic nevi)should be emphasized, as these visits may facilitate early detection of new primarytumors. Precursor Lesions Clinically atypical moles, also termed dysplastic nevi, occur in certainfamilies affected by melanoma. In some families, melanomas occur nearlyexclusively in the individuals with dysplastic nevi. In other families, the nevi maynot be present in all individuals with an increased risk of melanoma. Themelanomas may arise in clinically atypical moles or in normal skin (in the lattersituation the moles act as markers of increased risk). Individuals with clinicallyatypical moles and a strong family history of melanoma have been reported tohave a >50% lifetime risk for developing melanoma. Table 83-4 lists the featuresthat are characteristic of clinically atypical moles and that differentiate them frombenign acquired nevi. The number of clinically atypical moles may vary from oneto several hundred. Clinically atypical moles usually differ from each other inappearance. The borders are often hazy and indistinct, and the pigment pattern ismore highly varied than that in benign acquired nevi. Of the 90% of melanomapatients whose disease is regarded as sporadic (i.e., who lack a family history ofmelanoma), ~40% have clinically atypical moles, as compared with an estimated5–10% of the population at large. Further studies to determine the backgroundfrequency of clinically atypical moles are required, once greater unanimity existsregarding their clinical and histopathologic features. The observation that sporadicmelanomas can arise in association with a clinically atypical mole makes this themost important precursor for melanoma. Less frequent precursors include the giantcongenital melanocytic nevus. Congenital melanocytic nevi are present at birth orappear in the neonatal period (tardive form). The giant melanocytic nevus, alsocalled the bathing trunk, cape, or garment nevus, is a rare malformation thataffects perhaps 1 in 30,000 to 1 in 100,000 individuals. These nevi are usually >20cm in diameter and may cover more than half the body surface. Giant nevi oftenoccur in association with multiple small congenital nevi. The borders are sharp,and hair may be present. The lesions are usually dark brown and may have darkerand lighter areas. Pigment is haphazardly displayed. The surface is smooth torugose or cerebriform and may vary from one portion of the lesion to another. Table 83-4 Clinical Features Distinguishing Atypical Moles fromBenign Acquired Nevi Clinical Clinically Atypical Benign Acquired NeviFeature Moles Color Variable mixtures of tan, Uniformly tan or brown brown, black, or red/pink within a single nevus; nevi may look very different from each other Shape Irregular borders; Round; sharp, clear-cut pigment may fade off into borders between the nevus and surrounding skin; macular the surrounding skin; may be portion at the edge of the nevus flat or elevated Size ...