Ask the Expert: What Are Moles?

Justin Vujevick, MD

By Justin Vujevich, MD

Justin Vujevich, MD, FAAD is currently Director of Mohs Surgery at Vujevich Dermatology Associates in Pittsburgh, PA.  A graduate of Northwestern University Feinberg School of Medicine, Vujevich completed his dermatology residency at the University of Pittsburgh Medical Center and a fellowship in Mohs surgery and cutaneous oncology at the Texas Medical Center in Houston. He is past president of the Pennsylvania Academy of Dermatology and Dermatologic Surgery and also a member of The Skin Cancer Foundation’s Leonard Goldberg Fund for the Advancement of Mohs Surgery.


Q:   “I have a lot of moles on my body, and I understand that I should be regularly checking my skin to see if any of them might be dangerous. But I’m not exactly sure what to look for. How can I tell what mole might be a melanoma?”

AWhat Are Moles?
Moles are growths on the skin that are usually brown or black.  They are formed by clusters of melanocytes, the pigmented cells responsible for your skin color.  Moles typically appear during the first 30 years of life, can be flat or raised, and can darken with sun exposure, puberty, or pregnancy. 

How Do I Examine My Moles?
While the majority of our moles are harmless, some can become skin cancers called melanomas.  In fact, 1 in 50 Americans will be diagnosed with melanoma of the skin during their lives.  That’s why it is important to check our moles as part of a healthy lifestyle.  I recommend that patients examine their  skin once a month while in the shower.  Moles can be found on any part of your skin, so don’t miss those hard to see areas, including your scalp, back, genitals, palms and soles.  For these areas, use a mirror or photography, or have someone look at them for you.  Make sure to remove any polish when you check your fingernails and toenails, which can also be sites for melanoma.  

ABCDEs of Melanoma Detection
Now, what exactly should you look for? While moles can come in all shapes, sizes, and colors, you need to watch out for moles that have some or all of the criteria of the “ABCDEs” of melanoma detection.  These visual characteristics include:      

A=Asymmetry: One half of the mole looks different than the other half. 
B=Borders: The borders are uneven or not distinct.
C=Color:  Having a variety of colors is a warning sign. Look for color changes and different shades of brown, tan, black, white, red, grey or blue.
D=Diameter: The diameter of the mole is larger than a pencil head eraser, or about 6mm. 
E=Evolution: Look for any change in size, shape, color, or elevation, and stay alert to itching, pain, or bleeding.

The “Ugly Duckling” Sign
Not all melanomas are detectable through the ABCDEs, however. Another good recognition tool for melanoma detection is the “ugly duckling sign.”  Like trees in a forest, most moles on our skin should have a similar appearance.  However, if you find a mole that looks or feels different that the rest, point out this “ugly duckling” to your dermatologist. 

Dermatologists are trained to visually distinguish normal vs. atypical moles.  In addition, they may use a magnifying device called a dermatoscope to help with diagnosis.  Remember, when caught early, melanoma has an extremely high cure rate.  So don’t forget to examine your skin regularly, ideally every month.  

Published on November 16, 2015