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Dysplastic Nevi (Atypical Moles)

What Are Dysplastic Nevi?

Dermatologists classify moles as either common nevi or dysplastic nevi.

Common nevi are typically:

  • Small.
  • Round or oval.
  • A single color.
  • Smooth.

Nevi that appear atypical and show changes under pathologic evaluation that differ from normal nevi are called Dysplastic nevi, and have a very different appearance.

They are:

  • Larger (more than 5mm or ¼-inch in diameter).
  • Irregularly shaped around the edges or asymmetrical, such that one half does not match the other half.
  • More than one color and in particular, various shades of brown or red.
  • Change over time in size, shape, color, or surface texture/elevation.

A significant number of the population has atypical or dysplastic nevi, and while these may in some people be associated with melanoma, most are not. Atypical or dysplastic nevi are not skin cancers, and often do not become melanoma, although having them appears to increase your risk of developing melanoma, an aggressive and potentially deadly form of skin cancer.

You should visit the dermatologist or your primary care physician for annual skin cancer screening to watch for any changes or new growths.

It's not clear exactly what causes a dysplastic nevus to grow. Scientists believe UV light exposure plays a role.

People with fair skin, light hair, and freckles are more likely to have UV damage from the sun or indoor tanning, and to form dysplastic nevi. They're rare in Black, Asian, and Middle Eastern populations.

A related condition called familial atypical mole and melanoma syndrome runs in families. People with this condition can have more than 100 moles and increased numbers of atypical dysplastic nevi. They often appear in adolescence or early adulthood.

No one is certain why some people have atypical moles and others don't. However, because they can be risk markers for or turn into melanoma, it's crucial to be aware of other melanoma risk factors.

These include:

  • Having fair skin, light hair, and/or light-colored eyes.
  • Freckling easily.
  • Sun-burning easily and being unable to tan.
  • Having increased lifetime sun exposure, even if you tan and don't burn.
  • Experiencing repeated sunburns.
  • Having 50 or more common or atypical moles.
  • Having a personal or family history of skin cancer or melanoma.

Most dysplastic nevi do not turn into melanoma. However, because melanoma is the deadliest form of skin cancer, you should always have atypical moles checked and removed if they're suspicious.

If left untreated, and an atypical mole does turn into melanoma, it can spread deep into your skin and throughout your body.

There is no way we know to prevent common or atypical moles, especially if you're genetically at risk. However, protecting yourself from the sun reduces your risk and may result in fewer atypical moles. Sun protection will also reduce your risk of melanoma.

UV sunlight exposure causes about 90% of melanomas. To reduce your risk of melanoma, follow these recommendations:

  • Avoid spending time in the sun and avoid tanning beds.
  • Wear sunscreen every day when outdoors with an SPF of 30 or more.
  • Wear protective clothing when you are in the sun.
  • Check your own skin frequently.
  • Visit your dermatologist regularly to have skin exams.

Atypical moles that change in any way might be early melanoma.

Visit your dermatologist immediately if you notice any of the following signs or symptoms in an existing mole:

  • It changes color, shape, or elevation.
  • It gets bigger or smaller on one side or part.
  • The skin on the surface of a mole changes and becomes irregular or scaly.
  • It itches, bleeds, or oozes.
  • It becomes hard or lumpy.

Keep in mind that you can have moles anywhere on your body, even in areas without sun exposure. Your dermatologist or primary car physician can show you how to check your own skin at home and what changes to look for.

You can ask a friend or family member to look at your back, behind your ears, your scalp, or other areas you can't see. If they notice any spots, have a doctor examine them.

When you visit your primary care physician or dermatologist, they will examine all parts of your skin to determine if any spots are dysplastic nevi. During this exam, they'll measure and photograph any atypical moles, allowing them to watch for changes over time.

If an atypical mole hasn't changed, your doctor may not need to remove it.

Removing an atypical mole doesn't reduce the risk of new ones growing. However, if it looks suspicious, the dermatologist may remove it while you're in the office, and send it to a lab for a closer look.

Removing a dysplastic nevus takes about 15 minutes. You'll get a shot to numb the area beforehand so you won't feel any pain. Depending on the size of the nevus, your dermatologist can remove it in one of three ways:

  • Shave/saucerization biopsy. Your dermatologist or PCP shaves off thin layers of skin with a razor or scalpel. It may bleed but doesn't require stitches.
  • Punch biopsy. Your dermatologist or PCP uses a special tool with a small, circular blade to cut and remove a deeper section of tissue. Depending on the size of the cut, you'll need one or two stitches.
  • Excisional biopsy. Your dermatologist, surgeon, or PCP uses a scalpel to remove the atypical mole along with a small portion of healthy skin around it. The doctor will stitch the wound closed afterward, but you may have a small scar.

Your doctor will send your skin sample to a lab. There, a special doctor, called a pathologist, will examine it under a microscope it to determine if it's cancerous. As soon as your results are available, your doctor will call you to review and discuss them.

Before you leave the office, you'll get instructions on how to care for your biopsy site at home. Following those instructions will help you prevent infection. It may take a week or two to heal, and you may need to return to have stitches removed.

Early screening for dysplastic nevi helps catch melanoma before it has had a chance to spread. Your multidisciplinary team of specialists at UPMC Hillman Cancer Center provides a full range of individualized treatments based on your needs.

Medical treatment

Medical treatment for dysplastic nevi includes regular (at least annual) checkups with your dermatologist, medical oncologist, or surgical oncologist, so they can remove any moles that change or look suspicious. Ask your health care provider how often to come in for a skin check. The frequency will depend on your risk factors.

If your biopsy results show that you have melanoma, treatment will depend on whether or how much it's spread. Your medical oncologists may recommend nonsurgical treatments. These may include medicine in the form of a pill or shot to kill cancer cells and prevent them from spreading.

Surgical treatment

Surgical treatment isn't necessary for atypical moles unless your biopsy results show that you have melanoma. In that case, your surgeon will remove the primary tumor and a small section of the skin around it. Depending on the location of the melanoma, they may also remove lymph nodes that are close by.

Any other surgical treatment depends on the stage of your tumor and where it has spread. Your surgical oncologists will advise you on further treatments.

Lifestyle treatment

If you have melanoma or are at high risk, it's essential to:

  • Avoid direct sunlight between 10:00 a.m. and 4:00 p.m.
  • Apply sunscreen with SPF 30 or higher every day. Make sure you apply it to the tops of your ears, feet, and top of your head if they're exposed.
  • Wear protective clothing and a wide-brimmed hat when in the sun.
  • Stay in the shade whenever possible.
  • Always avoid tanning beds and booths.

UPMC Hillman Cancer Center is the only "Comprehensive Cancer Center" in the region recognized by the National Cancer Institute. Our dedicated team of specialists provides comprehensive, individualized, coordinated care for people with melanoma or other skin cancers.

We offer:

  • Complete screening and diagnostic services from dermatologists and pathologists.
  • Cutting-edge medical, radiology, and surgical skin cancer treatments.
  • Supportive care for our patients and their loved ones.

Contact Us About Melanoma and Skin Cancer Care

To learn more about melanoma and skin cancer care or to make an appointment, you can: