Melanoma: Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal, or "ugly looking." Thinking of "ABCDE" can help you remember what to watch for: Asymmetry - the shape of one half does not match the other Border - the edges are ragged, blurred or irregular Color - the color is uneven and may include shades of black, brown and tan Diameter - there is a change in size, usually an increase Evolving - the mole has changed over the past few weeks or months