This picture of a melanoma skin cancer tumor shows how they are often irregularly shaped and multicolored.
The earlier melanoma is detected, the better the chance for successful treatment. Monthly self-examinations may help find it early. Often, the first sign of melanoma is a change in the size, shape, or color of an existing mole. It also may appear as a new or abnormal-looking mole. The "ABCDE" rule can be used to help remember what to watch for.