Melanoma can develop two ways:

• In existing moles (also called nevi), even those present since birth or childhood
• in new growths appearing on the skin.

It can occur anywhere on the body, but is most often found on women's arms and legs, and on the head and neck or trunk (the portion of the body beginning from the hips and extending upward to the shoulders) of men. Melanoma can also develop on the feet (both tops and soles, and between toes) and hands (including between fingers and beneath the nail bed), and on the genitals.

Since developed melanoma is difficult to treat in later stages, it is extremely important to detect melanoma early. Regardless of skin cancer history, everyone should examine his or her own skin once monthly in addition to an annual skin examination performed by a physician. (Follow this helpful guide to learn how to perform a monthly self-examination.)

Those with a prior history of melanoma or other types of skin cancer may need to be examined by a physician more regularly. Any changing moles or new growths should be mentioned to a physician during each visit so that the physician can focus on those areas of the body specifically in addition to a complete skin exam.