Moles, or nevi, are skin growths made up of cells called melanocytes or nevus cells. The average person has fewer than 30-40 moles. Moles can be flat or raised and can range in color, and are primarily genetically determined, although ultraviolet (UV) exposure can play a role.
ATYPICAL MOLES are unusual-looking benign (noncancerous) moles, also known as dysplastic nevi (the plural of “nevus,” or mole). Atypical moles may resemble melanoma, and people who have them are at increased risk of developing melanoma in a mole or elsewhere on the skin. The higher the number of these moles someone has, the higher the risk. Those who have 10 or more have 12 times the risk of developing melanoma compared with the general population.
Heredity appears to play a part in the formation of atypical moles. They tend to run in families, especially in people with fair skin. Those who have atypical moles plus a family history of melanoma have a very high risk of developing melanoma. People who have atypical moles, but no family history of melanoma, are also at higher risk of developing melanoma compared with the general population. All of these high-risk individuals as well as rest of us should practice rigorous daily sun protection, perform a yearly skin examination head to toe with dermatologist and report any mole that changes.
Some people have so many normal and atypical moles that they are classified as having atypical mole syndrome. People with atypical mole syndrome usually have 100 or more moles, at least one of the moles is 8 mm or larger in diameter, and at least one or more moles atypical.
The ABCDE rule of melanoma or skin cancer are guidelines to help determine if a mole is normal or abnormal. A is for asymmetry, B is for Border, C is for Color, D is for Diameter, and E is for Elevation and/or Evolving. Normal moles generally follow the ABCDE rules: they are symmetrical, have smooth borders, have uniform color, are smaller than a pencil eraser in diameter, and are uniformly elevated above the skin surface and not changing over time. A normal mole that suddenly breaks the ABCDE rules might be abnormal or atypical,
A normal or common mole, also called a BENIGN nevus, is a growth on the skin that develops when pigment cells (melanocytes) grow in clusters. These growths usually occur on areas exposed to the sun. They are rarely found on the scalp, breast, or buttocks. Sometimes, common moles are present at birth, but they usually appear later in childhood.
A dysplastic nevus is a type of mole that looks different from a common mole. Some dermatologists use the term “atypical mole” to refer to a dysplastic nevus. These nevi (the plural form of nevus) may be bigger than a common mole. A dysplastic nevus’s color, surface, and border may all be different, and it is usually more than 5 millimeters wide. A dysplastic nevus can have a mixture of several colors, ranging from pink to dark brown. It usually is flat with a smooth, slightly scaly, or pebbly surface. These atypical moles have irregular edges that may fade into the surrounding skin.
Atypical nevi, also called dysplastic nevi, are acquired moles that have unusual features both in terms of how they look clinically and how they look when removed and examined. They tend to be asymmetrical, have irregular borders, be unevenly and/or very darkly colored, be larger than a pencil eraser, be unevenly elevated above the skin surface, or some combination of these findings.
If dermatologist or clinic identifies your moles as atypical, or if new moles appears, you may need a biopsy of one or more. Dysplastic nevi are atypical moles that have a greater chance of becoming skin cancer. The medical term “nevi” is the plural form of “nevus”, and a nevus is another name for a mole.
COMMONLY ASKED QUESTIONS
What should I do if I have dysplastic nevi?
You should go to a skin clinic or see a dermatology professional; everyone should protect their skin from the sun, and stay away from sunlamps and tanning booths. People who have dysplastic nevi, however, should take more precautionary steps to protect their skin, and should avoid getting a suntan or sunburn. Dermatologists recommend that people with dysplastic nevi check their skin often to prevent skin cancer. So, if you see any of the changes in a dysplastic nevus, you should tell your dermatologist or clinic. Changes to look for include:
- The color changes
- It gets smaller or bigger
- It changes in shape, texture, or height
- The skin on the surface becomes dry or scaly
- It becomes hard or feels lumpy
- It starts to itch
- It bleeds or oozes
What are the differences between a common mole, a dysplastic nevus, and a melanoma?
Common moles, dysplastic nevi, and melanoma vary by size, color, shape, and surface texture. Also, melanoma can spread to other parts of the body. The list below summarizes some differences between moles and cancer.
- Is it cancer? No. Common moles rarely become cancer.
- How many people have common moles? Most American adults—about 300 million people—have common moles.
- How big are they? Usually less than 5 millimeters wide, or about 1/4 of an inch (not as wide as a new pencil eraser).
- What color are they? Can be pink, tan, brown, black (in dark skin), or the person’s normal skin tone, and color is usually even.
- What shape are they? Usually round or oval, and has a distinct edge that separates it from the rest of the skin.
- What is the surface texture? Begins as a flat, smooth spot on the skin, and may become raised and form a smooth bump.
- Is it cancer? No. A dysplastic nevus is more likely than a common mole to become cancer, but most do not become cancer.
- How many people have dysplastic nevi? About 1 in 10 American adults—about 30 million people—have at least one of these.
- How big are they? Often wider than 5 millimeters (wider than a new pencil eraser).
- What color are they? May be a mixture of tan, brown, red or pink shades.
- What shape are they? Have irregular or notched edges, and may fade into the rest of the skin.
- What is the surface texture? May have a smooth, slightly scaly, surface, or a rough, irregular and pebbly appearance.