Dermatology A to Z
Malignant melanoma is a cancer of the pigment producing cells of the skin. Melanoma affects individuals of all ages. It is a very aggressive cancer and can rapidly spread to liver, lung, bone marrow and other organs. There is no good available treatment once the cancer spreads beyond the skin. The best treatment is early detection and removal while the cancer is still confined to the skin. Melanomas are usually dark skin lesions, with irregular borders, different colors of pigment, and sometimes a palpable thickness. Melanomas are often more than 6 mm in size. This kind of cancer is more common in Caucasians, in fair individuals and is related to sun exposure. Melanoma also can be hereditary and run in families. Current estimates are that 1 in 58 individuals will develop a melanoma sometime in their life. Individuals with certain kinds of pigmented skin lesions, large “birthmarks” (congenital nevi), multiple moles, unusual moles (dysplastic nevi) and who have had a previous melanoma are at much higher risk for melanoma.
Congenital nevi are pigmented (brown to black) skin lesions that have been present since birth. They may be small or very large covering large area of the skin (bathing trunk nevi). Congenital nevi may be quite thick and contain dark, thick hairs. The risk of melanoma occurring in a large dark congenital nevus is high and these lesions may be removed early in life if possible. The risk of melanoma in a smaller congenital nevus is controversial. Most physicians and dermatologists feel there is a significant risk of melanoma in these lesions and the majority recommends excision of such lesions before puberty if possible. If they are not or cannot be excised, they should be closely observed for size, color and appearance changes to detect melanoma early if it does occur.
Dysplastic nevi are unusual pigmented (brown) moles. Dysplastic nevi are usually more than 5 mm in size, have variation in color and indistinct “fuzzy or irregular” borders. Patients may have one mole or moles too numerous to count. Dysplastic nevi are found frequently in families and individuals with melanoma and are felt to be at high risk for malignant change. If you have one or two such moles, they will probably be excised; if you have several, you will need to be carefully observed (maybe even photographically) for changing moles. Individuals with many normal moles are also at higher risk for melanoma and should be observant for changes.
Melanomas may occur in any part of the skin or mucous membranes. This means the mouth, eyes, genital area, scalp, beneath finger and toenails, rectum, etc. If you have multiple nevi, dysplastic nevi, have had a melanoma or had a close blood relative with melanoma (father, grandparent, sibling or child), you need to have frequent complete skin exams. At least once a year this examination should be performed by a dermatologist, or other medical professional with a special interest, training and experience in skin disease. More frequently (once a month), you need to closely examine your own entire skin surface. You need to completely undress and methodically go over your entire skin surface using a full length mirror, a hand mirror and an assistant (spouse, etc.) Don’t forget to look inside your mouth and other body orifices and hard to see places. This approach will allow the early detection and treatment of a melanoma and is the only real chance for cure or prevention.