Moles (nevi) are benign skin lesions that appear on any part of your body at any time in your life. Some moles may turn malignant over time. Their course is genetically determined, but exposure to the sun or tanning beds can alter them. When moles change, they can become a deadly form of skin cancer called melanoma. Periodic self-exams and annual professional exams are necessary to find and diagnose melanoma early.
What are moles?
Moles are harmless skin lesions that arise from pigment-producing cells in the skin called melanocytes. These melanocytes will cluster together and grow to form a mole. Moles can come in any size or shape, such as raised or flat, and they can be any color, such as pink, tan, brown, or black.
When do moles appear?
There are two basic types of benign moles based on when they appear during your life.
- Congenital Nevi: These moles are present at birth. They can be small, medium, or large-sized. If they are large, they have a higher risk of becoming cancerous.
- Acquired Nevi: These moles arise at any time in your life after birth. Some moles can change into melanoma because of genetics, exposure to the sun's ultraviolet (UV) rays, or the radiation from tanning beds. It is worrisome if a mole develops after your 30s.
How to check your moles at home?
Self-exams at home are critical for detecting new moles or changes in existing moles. If melanoma is detected early, the prognosis is excellent, and the cure rate is 99%. Dermatologists recommend self-exams every three months. If you have a personal or family history of melanoma, you should perform your self-exams monthly.
Here are some of the warning signs of melanoma, also known as the ABCDEs. Look for these signs when you are doing your self-exams. If you notice any of the following changes in your moles, see your dermatologist immediately.
A is for Asymmetry. If you draw an imaginary line through the middle of the mole, the two halves would not be identical.
B is for Borders. The mole's borders are ill-defined, jagged, irregular, or blurred.
C is for Color. The mole contains several colors such as pink, red, white, blue, purple, tan, brown, or black.
D is for Diameter. A mole bigger than 6 mm (pencil eraser) is worrisome. However, we know that melanomas may be any size, so do not disregard a changing mole if it is less than 6 mm.
E is for Evolving. The most important warning sign is if the mole has rapidly evolved and changed size, shape, or color. Also, if the mole begins to hurt, itch, or bleed, this is a warning sign.
Another warning sign is the "ugly duckling" sign. An "ugly duckling" mole is one mole on your body that looks completely different from your other moles.
When do you get your moles checked by a professional?
Everyone should have their skin checked annually by a dermatologist. Dermatologists are physicians trained to detect melanoma and other types of skin cancer. If you notice any changes in your moles, see your dermatologist immediately. If detected early, melanoma is usually curable.
If you have skin cancer or melanoma history, you are at risk of developing other skin cancers in the future. You will need to see your dermatologist more frequently, possibly every three months. Here are common forms of non-melanoma skin cancers.
- Basal cell carcinoma
- Squamous cell carcinoma
If you have risk factors for melanoma, you will need to see a dermatologist more frequently, possibly every six months. Here are some risk factors.
- Tanning bed use
- Several sunburns
- Fair skin, light eyes, and light hair
- Regular heavy exposure to the sun
- Many moles
- History of dysplastic (atypical) moles
How can I keep my skin healthy?
Sun protection is key to keeping your skin healthy. It can help prevent a mole from becoming melanoma and the development of other types of skin cancers. Here are ways you can protect your skin.
- Avoid peak hours of sun exposure: 10 am-4 pm.
- Seek shade when you are outside.
- Limit your sun exposure.
- Do not use tanning beds. They are more deadly than the sun's radiation.
- Use a broad-spectrum sunscreen (UVA and UVB coverage) with at least SPF 30 daily. SPF 50 is better.
- Re-apply your sunscreen every 1-2 hours that you are outside. This includes driving in the car or sitting by a window.
- If you are sweating or in the water, re-apply your sunscreen every 40 to 60 minutes.
- Use sunscreen on cloudy and rainy days.
- Use sun protection gear such as wide-brimmed hats, gloves, UPF sun protection clothing, and sunglasses when you are outside.
- Use chapstick with SPF 30-50 for your lips and re-apply every 1-2 hours.
- Use sun protection even on cloudy, rainy, and cool days.
Moles are harmless skin lesions that have the potential to become cancerous. This malignant transformation to melanoma can occur due to genetics, exposure to the sun, or tanning bed use.
It is vital to protect yourself daily from the cancer-causing radiation of the sun and avoid tanning beds. If caught early, almost all melanomas are curable.
Periodic self-exams and annual dermatologic exams are critical to survival. Always be on the lookout for any changes (ABCDEs) in your moles or the appearance of new moles.
If you notice changes or new moles, see your dermatologist right away.
Prompt diagnosis and treatment can mean the difference between life and death.
American Academy of Dermatology Association. Moles.
American Cancer Society. Melanoma Skin Cancer.
Bolognia, J., Jorizzo J.L., Schaffer, J.V. (2012). Dermatology. Philadelphia: Elsevier Saunders.
Kunishige, J. H., Brodland, D. G., & Zitelli, J. A. (2012). Surgical margins for melanoma in situ. Journal of the American Academy of Dermatology.
Skin cancer Foundation. Melanoma.