Cutaneous malignant melanoma

Abstract

Malignant melanoma is the leading cause of death as a result of skin disease in the United States. The incidence of melanoma has increased exponentially during the last two decades, and the disease is now the eighth most common cause of cancer in the United States, with an estimated annual incidence of approximately 13 per 100,000. Melanoma is curable if diagnosed and treated early in its course, but unfortunately, many patients are still diagnosed with invasive melanoma; the 5-year survival rate for those diagnosed with melanoma that has spread to. regional lymph nodes is 50%. Careful physical examination of pigmented lesions and attention to the clinical history guide the physician toward establishing a diagnosis. The early warning signs of melanoma are a change in the size, shape, or color of a lesion and symptoms associated with pigmented lesions, such as pruritus; ulceration and bleeding are generally late findings in primary melanoma. The ABCD guide for diagnosis of melanoma includes Asymmetry of the lesion, Border irregularity with notching, scalloping, or poorly defined margins, Color variegation, and Diameter greater than 6 mm. The diameter of a lesion should not be used to exclude otherwise suspicious lesions because small diameter melanomas are reported. The cause of melanoma is still unknown but is thought to involve exposure to ultraviolet radiation, possibly years before the tumor is apparent. The increase in incidence of malignant melanoma is probably related to many factors, including increased time spent in outdoor recreational activities, changes in employment trends, and clothing that exposes more skin. A familial form of melanoma exists in cases in which afflicted individuals have large numbers of nevi and melanoma is found in one or more first- or second-degree relatives. These individuals have an almost 100% lifetime risk of developing melanoma. For others, common risk factors include a fair skin type, large numbers of moles, and a history of excessive sun exposure, including sunburning, early in life. Treatment of melanoma is directed at surgical excision of the primary tumor. Adequate excision of thin primary melanoma results in an excellent prognosis. Treatment of melanoma that has metastasized regionally is primarily surgical, and treatment of widespread disease primarily includes chemotherapy-based regimens. The prognosis of advanced-stage disease is poor, and several experimental treatment protocols are being evaluated.