A is for asymmetrical shape. Look for moles with irregular shapes such as 2 very different looking halves.
Look to see if the mole or lesion has an irregular border. These could be borders that are irregular, notched, or scalloped.
Look for changes in color. Look for moles or lesions that have many colors or an uneven distribution of color.
Look for new growth in a mole larger than ¼ inch (about 6 millimeters).
i.e. changing over time. This is the most important symptom of all. Suspicious symptoms in a mole may include: itching, oozing, bleeding, or a sore that does not heal. Rarely is pain involved.
Cancerous (malignant) moles vary greatly in appearance. Some may show all the changes listed above while others may have only one or two unusual characteristics.