Causes of Moles
Although doctors do not know the exact cause of moles, research suggests that they are a result of genetics and sun exposure. A mole occurs when melanocytes, the pigment-producing cells in the skin, grow in a cluster. New moles may appear as a result of aging, fair skin, sunburn or reactions to drugs such as hormones or antibiotics.
Types of Moles
Dermatologists characterize moles by several factors, including physical appearance, when they emerge and their risk of becoming cancerous.
Acquired Moles (Common moles)
Common moles emerge after birth, or shortly after, but usually during the first 20 years of life. However, they can appear at any age. It is usual for adults to have 10 to 40 acquired moles. Acquired moles have distinct edges and are flat or slightly raised. They are round or oval in shape and uniform in color. A person with more than 50 common moles may be at a higher risk of developing melanoma. However, common moles are usually non-cancerous.
Congenital moles are present at birth and are commonly called birthmarks. Smaller congenital moles should be monitored for changes, but do not usually need treatment. Larger congenital moles that are between 7 cm and 14 cm on an infant present a higher risk of developing a melanoma. These moles require regular monitoring by a dermatologist and may need to be removed with surgery.
Also called “atypical moles,” dysplastic nevi are larger than common moles and have uneven coloration that seems to fade at the edges. They also have irregular borders and can have a pebbled or scaly texture. Atypical moles can appear anywhere on the body but are more common on the trunk.
Dysplastic moles can have similar characteristics to melanoma. They are not cancerous; however, people with more than four atypical moles or a family history of melanoma are at a higher risk of a dysplastic mole turning into melanoma. It is essential to have moles monitored by a dermatologist to identify any changes in appearance.
Warning Signs of Melanoma
Melanoma is the deadliest type of skin cancer. It begins in the melanocytes and can spread to other parts of the body. Because early detection and removal is critical to successfully treating cancer, the American Academy of Dermatology (AAD) advises the regular monitoring of moles to identify new moles or changes in old moles.
The AAD offers the ABCDE’s of melanoma to help identify when a mole may require medical attention:
Asymmetrical: One part of the mole does not match the rest of the mole.
Border: Uneven, no clear border
Color: Variations in color or changes in color over time
Diameter: Increases in size to more than ¼ of an inch
Evolving: Change in appearance (color, border or size, sore, bleeds, itches)
Anyone can get melanoma. However, people with fair skin tones have a higher risk of melanoma. Caucasian men are most likely to have melanoma on their back and trunk; Caucasian women are most likely to have melanoma on their lower legs and arms. Melanoma in people with darker skin tones often develops in different locations, including beneath the fingernails, toenails, on the palms or soles.
Treatment of Moles
Most moles are non-cancerous and do not require treatment. A dermatologist often removes common moles for cosmetic reasons or if the location of the mole interferes with dressing, shaving or other daily tasks. Moles can be removed relatively easily, quickly and safely using one of two common treatments. In both methods, the mole will be tested for cancer cells after removal.
Surgical Shave: Using a special blade, the doctor will cut around and underneath the mole to remove it. This method does not require stitches.
Surgical Excision: The doctor will cut out the entire mole, including some of the skin underneath and surrounding skin. This method usually requires suturing.
If you notice the appearance of a new mole as an adult or change in an old mole, you should see your dermatologist right away. The earlier a mole is treated, the better. For anyone who is at a higher risk of melanoma, regular skin checks by a dermatologist are recommended. Risk factors can include:
- History of severe sunburns
- Long-term exposure to sun
- More than 50 common moles
- More than four atypical moles
- Family history of melanoma, atypical moles
- Fair skin, light-colored eyes or light or red hair
- Use of medicines that cause sun sensitivity