The average baby is born without a single mole, but the average person has a few of these so-called beauty marks — if not dozens — by the time they reach adulthood. These skin growths are exceptionally common, and most are harmless.
Sometimes, though, a new mole or a changing mole can be cause for concern.
As board-certified dermatologists who offer head-to-toe preventive skin cancer screenings at Manhattan Dermatology, our team knows that patient education is just as important as having regular skin checks — especially when it comes to spotting risky moles.
Moles, also known by the medical term “nevi” (nevus in the singular), are the most common pigmented lesion, or skin growth that consists of pigmented skin cells (melanocytes). Age spots (lentigines) and sun freckles are other types of pigmented lesions.
Moles can grow anywhere on your skin or mucous membranes. Although they typically start emerging in childhood, many people continue developing new moles until about the age of 40. Whether they grow alone or in clusters, nevi are most likely to appear on sun-exposed skin.
The average adult has about 10-40 moles, and some people have many more. Most moles are normal and harmless, but not all moles are the same. Knowing how to differentiate between typical and atypical nevi is important, especially if you have a lot of moles. Nevus types include:
These are the normal moles that most people have. Many are evenly pigmented (pink, tan, brown, or black), but some blend into their surrounding skin tone. Common moles are usually small (less than a quarter inch across), flat, smooth, round or oval, and have a distinct edge that separates them from the surrounding skin.
While many common moles don’t ever change, some become slightly raised over time, gradually lighten, or slowly fade away. Any mole you develop on your skin after you’re born is called an acquired mole. Most common nevi are acquired moles.
About one in 100 people (1%) have congenital moles, or nevi that were on their skin at birth. These moles may be small or large; large congenital nevi are associated with an increased risk of melanoma, the most aggressive and deadliest form of skin cancer.
These rare moles develop in the first 20 years of life, usually during childhood. Raised and dome-shaped, Spitz nevi can look like melanoma. They may be pink, red, brown, or black; they may also bleed or have an opening that oozes.
A dysplastic nevus is a mole that looks distinct compared with a common mole. Also referred to as atypical moles, these nevi may be larger than a quarter inch across, contain a mixture of shades (tan and brown or pink and red), have irregular, notched, or faded edges, or feel pebbly and rough to the touch.
About one in 10 people (10%) have at least one dysplastic mole. Dysplastic nevi rarely change and become cancerous, but they’re more likely than a common mole to turn into a melanoma. People who have many moles are more likely to have more dysplastic nevi, too.
Even though dysplastic nevi rarely turn into melanoma, they’re considered a risk factor for this aggressive skin cancer. Having more than five atypical moles makes you 10 times more likely to develop melanoma compared with someone who has no dysplastic nevi.
A dysplastic nevus doesn’t have to be removed, but it does require regular monitoring to check for changes over time. Why? Most melanomas (about 70%) start in normal skin, but the 30% of melanomas that begin in existing moles are likely to appear as a changing dysplastic mole.
This is where the ABCDEs of melanoma come in. This standard mole-checking tool aims to catch changing common and dysplastic moles, or any mole that appears overly suspicious. Concerning moles tend to have one or more of the following qualities:
Any change in a mole’s size, shape, or color is cause for concern, especially if the change happens quickly. Our team should also assess any mole that has started bleeding, oozing, crusting, or feeling itchy, as well as new moles that appear after the age of 30.
Are you worried about a suspicious-looking mole? When in doubt, have us check it. To schedule a prompt mole evaluation, contact your nearest Manhattan Dermatology office in the Murray Hill or Midtown East neighborhoods of Manhattan, New York City, today.
