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Moles are small growths on the skin. They typically appear as light to dark brown spots on the skin that are either flat or raised. Most people have benign moles, which are harmless.
Moles that become atypical (called dysplastic nevi) can eventually become melanoma. Melanoma is a form of skin cancer. Moles that change or look atypical need to be evaluated by a dermatologist.
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Moles develop from pigment-producing cells in the skin called melanocytes. These cells form a cluster, causing the mole.
These factors increase your chance of developing moles. Tell your doctor if you have any of these risk factors:
- Moles present at birth (This increases the likelihood of more moles later in life.)
- Family members who have moles
- Excessive exposure to sunlight, especially sunburn
Most people have some benign moles that appear at birth, childhood, or adolescence.
Benign moles, which can appear anywhere on the body, are usually:
- Dark brown, but can also be yellow-brown or flesh tone
- One color
- Round or oval with distinct edges
- Flat and smooth, but may occasionally become raised, rough, grow hair, or change color over time
Signs that a mole may be atypical include:
- Sudden change in size, color, shape, texture, or sensation
Large size (¼ inch or more across, about the size of an eraser at the end of a pencil)
- Many melanomas are smaller than this size.
- A mixture of colors, often including black
- Irregular edges
Abnormal surface that is:
- Open with a sore that won't heal
- Hard and raised lump
- Itchy, tender, or painful
- Abnormally colored skin around it
Irregular Border on Mole
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The doctor will examine your skin and ask about your symptoms and medical history.
Tests may include:
- Biopsy—removal of all or part of the mole to be tested for cancer cells
Benign moles do not need to be treated. However, surgery may be done to remove those that are unsightly or irritated.
Treatment for atypical moles include:
Atypical moles that are cancerous or suspected of being cancerous can be removed. The mole tissue is examined under a microscope. If cancer cells are found, more surgery is done to remove any remaining portion of the mole and surrounding tissue.
To help prevent benign moles from becoming atypical (and possibly cancerous):
- Avoid spending too much time in the sun.
- Protect your skin from the sun. For example, wear a shirt, wide brim hat, and sunglasses.
- Use sunscreen with a sun protection factor (SPF) of at least 15.
To detect atypical or cancerous moles early:
- Monitor your moles, especially atypical ones.
- Report any changes in a mole to your doctor.
Have your doctor check and monitor atypical moles on a regular basis. Have moles checked more often if you have:
- A large number of atypical moles
- A family or personal history of atypical moles that develop into melanoma
Have moles removed if your doctor recommends it.
American Academy of Dermatology
American Cancer Society
Canadian Dermatology Association
Berkow R, Merck Research Laboratories. The Merck Manual of Medical Information—Home Edition. New York, NY: Simon and Schuster, Inc; 2000.
Moles. American Academy of Dermatology website. Available at: http://www.aad.org/dermaz/Default.aspx. Accessed July 29, 2008.
Moles. Mayoclinic website. Available at: http://www.mayoclinic.com/. Updated February 2008. Accessed July 29, 2008.
What you need to know about moles and dysplastic nevi. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/wyntk/moles-and-dysplastic-nevi. Updated September 2002. Accessed July 29, 2008.
Last reviewed February 2008 by Ross Zeltser, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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