A melanoma, in contrast, often has notched or indistinct borders that may signal ongoing growth and spread of the cancer. One of the earliest signs of melanoma may be the appearance of various colors within the lesion. Because melanomas arise within pigment-forming cells, they are often varicolored lesions of tan, dark brown, or black, reflecting the production of melanin pigment at different depths within the skin. Occasionally, lesions are flesh colored or surrounded by redness or lighter areas of depigmentation. No matter what size, any suspicious lesion should be examined by a physician.
Most melanomas tend to be flat initially and spread laterally across the skin surface as they grow.
At this early stage, which can last from one to five years or longer, removal of the growth has an excellent chance of curing the melanoma. Lesions that become raised or dome-shaped over at least part of their surface indicate that downward growth has occurred. In some cases, this growth is very rapid, occurring over a period of weeks to months. Any lesion that grows quickly or that is partially flat and partially raised should be checked immediately. Advanced melanoma that has spread beyond the skin can cause a variety of symptoms, including fatigue, weight loss, headaches, and bone pain, depending on where it has spread.