Atypical Mole/ Dysplastic Nevus

Dysplastic Nevus/Atypical Mole


Dysplastic Nevus/Atypical Mole

A dysplastic nevus or atypical mole is a nevus (mole) whose appearance is different from that of common moles.

Dysplastic nevi often grow to larger than ordinary moles, and may have irregular and indistinct borders. Their color may not be uniform, and may range from light pink to very dark brown. They usually begin flat, but parts may raise above the skin surface.

According to the National Cancer Institute, researchers have shown that atypical moles are more likely than ordinary moles to develop into a type of skin cancer called melanoma. Although most atypical moles may never become malignant, numerous studies indicate that about half of melanomas arise from atypical moles. Epidemiology studies have also shown that individuals with multiple dysplastic nevi are at much higher risk for developing melanomas.

Patients with a personal or family history of skin cancer or of dysplastic nevus syndrome (multiple atypical moles) should see a dermatologist at least once a year to be sure they are not developing melanoma.

Risk Factors

People tend to inherit a tendency to develop atypical moles. Atypical moles are not cancerous, but people who have these moles have a higher risk of malignant melanoma, an aggressive and deadly form of skin cancer. Your risk of melanoma increases if you have atypical moles, have had a previous melanoma or a first-degree relative (parent, sibling, child) who has had a melanoma. A mole that stands out and looks different from other moles (known as the "ugly duckling" sign) can be dangerous and should be evaluated by a dermatologist.


American Academy of Dermatology



Not all atypical moles need treatment. If there is concern that an atypical mole might be a melanoma, then a biopsy will be performed. This is the best way to diagnose skin cancer. To perform a biopsy, your dermatologist will remove either the entire mole or part of it. The removed skin will be sent to a lab where it will be examined under a microscope.


The most important thing you can do to protect your skin and prevent skin cancer is to limit sun exposure. Sun exposure is the most preventable risk factor for all skin cancers, including melanoma. The following behaviors can help prevent new skin cancers:

  • Seek shade.
    Shade helps protect your skin from the sun’s harmful UV rays. Shade is especially important between 10 a.m. and 2 p.m. when the sun’s rays are strongest. But any time your shadow is shorter than you are, seek shade.
  • Wear protective clothing.
    This means wearing a long-sleeved shirt, pants, a wide-brimmed hat, and sunglasses, when possible.
  • Generously apply sunscreen that offers broad spectrum (UVA and UVB) protection, water resistance, and a Sun Protection Factor (SPF) of 30 or more.
    Studies have shown that wearing sunscreen every day can reduce the risk of developing melanoma by half. Even on cloudy days, apply sunscreen to all skin that will not be covered by clothing. Reapply approximately every two hours, or after swimming or sweating.
  • Take care around water, snow, and sand.
    These reflect and intensify the damaging rays of the sun.
  • Avoid tanning beds.
    Ultraviolet light from the sun and tanning beds can cause skin cancer and wrinkling. If you want to look like you’ve been in the sun, you may wish to use a sunless self-tanning product, but you should continue to use sunscreen with it.


American Academy of Dermatology


What should I do if I have an atypical mole?

You should watch all atypical moles for signs of change. Changes in an atypical mole can be a sign of melanoma. If you notice that a mole is changing in color, size or shape, or is itching or bleeding, immediately contact your dermatologist. When found early and treated, melanoma has a high cure rate.

What is familial atypical mole-melanoma (FAMM) syndrome?

If you have many atypical moles, your dermatologist may talk with you about FAMM syndrome. Having this syndrome greatly increases your risk of developing melanoma. If you have FAMM syndrome, you will have many moles (often more than 100) and some of your moles will be atypical. Also, a first-degree relative (parent, sibling, or child) or second-degree relative (grandparent, grandchild, aunt, or uncle) has had melanoma.

What should I do if I have FAMM?

If you have FAMM, your dermatologists may recommend that you:

  • Have a full-body screening from a dermatologist every three to 12 months, beginning at puberty.
  • Examine your skin at least once a month. If you need to learn how to do this, be sure to tell your dermatologist.


American Academy of Dermatology
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