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Malignant Melanoma

Of the skin cancers, melanoma causes the largest number of deaths. This tumor can appear
at any age but most commonly occurs in persons between 30 and 60 years of age. Because
solar radiation may act as a cocarcinogen or promoter, it may be related to the onset of
melanoma. This hypothesis is supported by the fact that populations closest to the equator
have the highest prevalence of melanoma and the fact that melanoma has a

Important risk factors for cutaneous melanoma include light skin, hair, and eyes; a history
of sun sensitivity; high exposure to intermittent intense sunlight, especially during
childhood; impaired DNA repair of UV injury, as in xeroderma pigmentosum; and

The interaction between melanoma and vitiligo remains to be clarified. Some authors
postulate that patients with vitiligo have a lower incidence of melanoma,35 whereas others
report that vitiligo is more common in patients with melanoma than in age-matched control
melanoma, malanoma, melenoma, skin cancer

Melanomas commonly arise from preexisting nevi but may arise de novo from epidermal
melanocytes. Common sites are the head, the neck, and the trunk in males and the extremities,
especially the legs, in

Melanoma may also arise in congenital melanocytic nevi [see Subsection XI], especially
those greater than 20 cm in diameter (often termed giant congenital nevi when involving a
large surface area of the body). The estimated occurrence is five to 20 percent during a
lifetime, but such malignant transformation usually occurs by 10 years of age.37 Characteristic histologic
features of giant congenital nevi include deep dermal extension of melanocytes
with adnexal involvement and neural differentiation. The potential risk of melanoma in smaller
congenital pigmented nevi, which may lack these histologic features, has not

Several clinical types of melanoma have been recognized. Lentigo maligna melanoma and
superficial spreading melanoma are characterized by an early horizontal growth phase in the
epidermis, which is followed after a variable period by dermal invasion that results in a
nodular lesion. Acral lentiginous melanoma occurs on palmar, plantar, and mucosal surfaces.

Superficial spreading melanoma, the most common type of melanoma, begins as a small,
irregular, brown-pigmented lesion with various shades of red, white, and blue.
There is diffuse intraepidermal distribution of relatively monomorphous, large malignant
melanocytes in noninvasive areas. After a variable period of superficial growth, usually
ranging from one to five years, papules or nodules signifying vertical growth appear.

Acral lentiginous melanoma, the most common form of melanoma in blacks, occurs on the
non–hair-bearing sites, such as the soles, the palms, the digits, subungual and periungual
areas, and mucosal surfaces. Lesions are more common in patients older than 60 years.39 The

In 34 of 35 cases of nonmucosal acral lentiginous melanoma reviewed in one study, the
lesions were located on the soles. Twenty-five percent of the patients gave a history of

Nodular melanoma first appears as a rapidly growing papule or nodule with a smooth, scaly,
eroded, or

Desmoplastic melanoma, a rare but distinct type of melanoma that may be mistaken for
invasive fibromatosis or fibrosarcoma, consists of a deeply infiltrating nodule with a spindle

Treatment of histologically proven melanoma consists of surgical excision. The width of the
margin of normal skin that is removed depends on the thickness and location of the

Additional surgical treatment, such as lymph node dissection, depends on such factors as

Lymphoscintigraphy followed by selective lymphadenectomy has been proposed as an
alternative to routine elective lymphadenectomy or clinical follow-up for management of
early-stage melanoma. Lymphoscintigraphy is an intraoperative procedure involving injection

Adjuvant treatment with immunotherapy or chemotherapy may palliate patients with
advanced disease. Metastatic melanoma treated with dacarbazine as a single
chemotherapeutic agent has a response rate of 15 to 18 percent. It is known that endocrinefactors may influence the course of melanoma. In 117 randomized patients, the combination of dacarbazine plus tamoxifen was more effective in women than dacarbazine alone

An experimental immunologic approach with potential therapeutic applications couples an
analogue of melanocyte-stimulating hormone with a monoclonal antibody to the CD3 T cell

Other immunologic approaches for advanced melanoma that are currently being
investigated include the use of cytokines such as interferons and interleukins alone or in
combination with cytostatic agents. Improvement in survival using a polyvalent melanoma
vaccine derived from cultured melanoma cell lines was studied in 82 patients with stage III

Immunotherapy with high-dose interleukin-2 (IL-2) has led to long-lasting antitumor
response in patients with metastatic melanoma.58 Of 134 patients with metastatic melanoma