Malignant melanomas are a group of malignant neoplasms, primarily on the skin, that are composed of melanocytes (melanin- producing cells) (8, 17). Most melanomas develop from a pigmented nevus over a period of several months or years and occur most commonly in fair-skinned people with light-colored eyes. A previous sunburn can increase the risk of a person developing a melanoma. Any black or brown spot having an irregular border, pigment appearing to radiate beyond the border, a red, black and blue coloration observable on closer examination, or a nodular surface is suggestive of melanoma and is usually excised for biopsy (17). This paper will look at the classification, epidemiology, diagnosis, genetics, treatment, and prognosis of malignant melanomas.
Melanomas occur in several different types: amelanotic melanoma, juvenile melanoma, lentigo malignant melanoma, nodular melanoma, primary cutaneous melanoma, and superficial spreading melanoma (17). Melanoma can spread and cause tumors to develop in other areas of the body (8). Melanomas usually occur in families with a history of melanoma, in people who have had lengthy exposure to the sun and/or have had sunburns, or exposure to tar or arsenic (8).
Cutaneous malignant melanoma, once considered a rare tumor, is now the fourth commonest cancer in Australia and New Zealand, the tenth in the Unites States, Canada, and Scandinavia, and the eighth in Great Britain. The increase in the incidence of melanoma and its mortality rates appear to be related to new lifestyles and to new patterns of exposure to potential carcinogenic agents (24). In a population of mainly European origin, a substantial proportion of the increased incidence is attributable to a steady change from predominantly occupational to predominantly recreational exposure to solar radiation, according to these authors.
In the United States, the incidence of melanoma varies with latitude, with more than ...