Moles are spots on the skin where pigmented cells have clustered together. 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 are called dysplastic nevi. They may eventually become melanoma. Melanoma is a form of skin cancer.
Moles develop from pigment-producing cells in the skin called melanocytes. Normally, these cells are evenly distributed in your skin. When you have a mole, these cells have formed a cluster.
Factors that may increase your chance of developing moles:
- Moles that are present at birth increase the likelihood of more moles later in life
- Family members with moles
- Excessive exposure to sunlight, especially sunburn
Most people have some benign moles that appear at birth, childhood, or adolescence. Most adults have 10-40 moles.
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, or grow hair
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
- A mixture of colors, often including black
- Irregular edges
Abnormal surface that is:
- Open with a sore that will not heal
- Hard and raised lump
- Itchy, tender, or painful
- Abnormally colored skin around it
Irregular Border on Mole
The doctor will examine your skin and ask about your symptoms and medical history.
Your bodily tissues may be tested. This can be done with a biopsy to remove 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 monitoring or removal. 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 moles
- A family or personal history of atypical moles or melanoma
Have moles removed if your doctor recommends it.
American Academy of Dermatology
American Cancer Society
Canadian Dermatology Association
Moles. American Academy of Dermatology website. Available at: http://www.aad.org/dermatology-a-to-z/diseases-and-treatments/m---p/moles. Accessed August 27, 2014.
Common Moles, Dysplastic Nevi, and Risk of Melanoma. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/cancertopics/factsheet/Risk/moles. Updated November 2011. Accessed August 27, 2014.
Last reviewed June 2014 by Fabienne Daguilh, 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.