Definition of Melanoma  

Melanoma is the most serious form of skin cancer. It begins in the pigment cells (melanocytes, see diagram right) that produce skin color. Most melanomas can be treated successfully if they are detected at an early stage. If melanoma is not detected at an early stage, it can spread to other parts of the body and is potentially a lethal form of cancer.

Since most pigment cells are in the skin, most melanomas start on the skin. They can occur in the eye and rarely in the membranes of the nasal passages, oral, pharyngeal mucosa, vaginal and anal mucosa.

Most melanomas (70%+) begin in or near an existing mole or dark spot on the skin. It is important that you know the size, color and location of moles on your body so that you can take note of changes in existing moles or the appearance of new moles. Some "birthmarks" (congenital moles) can also develop into melanomas.

Ordinary Moles are evenly colored, have sharply defined edges and are round or oval in shape. They can be flat or raised and are less than 6 millimeters (1/4") in diameter (about the size of a pencil eraser). Melanomas have an irregular appearance and are usually larger than an ordinary mole.

Information provided courtesy
of Chiron Corporation

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