How can I determine if a mole is benign or precancerous?

When evaluating a mole to determine whether it is benign or precancerous, it pays to remember the A-B-C-D's of skin cancer warning signs:

• Asymmetry – the 2 halves of the mole won't match, in other words, they do not form a perfect circle

• Border – uneven borders can signal cancer, with scalloped or jagged edges

• Color – multiple colors are a warning sign whereas benign moles are mostly a single color

• Diameter – one quarter inch or larger for squamous cell cancer, basal cell cancer, however melanomas can be smaller and still deadly.

There is a memory aid we like to use when examining moles to decide whether or not we should be concerned about cancer in a mole -- ABCDE; A: asymmetry of the mole itself, should be mostly even with smooth borders; B: border, as above, should be even and smooth; C: color, even and one color; D: diameter, should not be bigger than a pencil eraser; and E: evolving, if a mole that you've had forever is changing, you should bring it to your doctor's attention. If you have noticed any of these changes in a mole you have, you should see your doctor.