If you draw a line through this mole, the two halves will not match.
Having a variety of colors is another warning signal. A number of different shades of brown, tan or black could appear. A melanoma may also become red, blue or some other color.
Melanomas usually are larger in diameter than the size of the eraser on your pencil (1/4 inch or 6 mm), but they may sometimes be smaller when first detected.
Any change – in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching or crusting – points to danger.