Dysplastic or atypical nevi/moles have a potential of progressing into melanoma.

Early signs that would suggest malignant change include:

• Asymmetry: Half the lesion does not match the other half.
• Border irregularity: The edges are ragged, notched, or blurred.
• Color variegation: Pigmentation is not uniform and may display shades of tan, brown, or black; white, reddish, or blue discoloration.
• Diameter: A diameter greater than 6 mm (greater than pencil eraser) is characteristic, although some melanomas may have smaller diameters; any growth in an existing nevus warrants an evaluation.
• Evolving: Changes in the lesion over time; changes include an increase in size, itching, or the development of satellites. Ulceration and/or bleeding are later signs.