Atypical Moles & Your Skin

The Facts. The Risks. How They Affect You.

People with 10 or more atypical moles have
12x THE RISK OF
MELANOMA

Atypical moles, also known as dysplastic nevi, are unusual-looking moles that have irregular features under the microscope. Though benign, they are worth more of your attention because individuals with atypical moles are at increased risk for melanoma, a dangerous skin cancer.

An atypical mole can occur anywhere on the body. The appearance of these moles can vary greatly. The best advice is to know your skin. Keep track of any and all moles you may have, to give you the best chance to spot anything new, changing or unusual and bring it to the attention of your dermatologist.

What you need to know

  • An atypical mole is not a skin cancer but having these moles is a risk factor for developing melanoma.
  • Although rare, melanoma can arise in association with atypical moles. That is why it is important to be aware of these moles, get them checked by your dermatologist, and watch out for changing moles.
  • If you have atypical moles plus a family history of melanoma, you have an increased risk of developing melanoma.
  • If you have any common melanoma risk factors plus atypical moles, you must be particularly watchful:
    • Fair skin, light eyes or hair
    • Freckles
    • Many moles
    • A personal or family history of melanoma or nonmelanoma skin cancer
    • Photosensitivity
    • Inability to tan
    • Repeated and intermittent sunburns

It’s important to note that even without a family history of melanoma, if you have atypical moles, you have an elevated risk of developing melanoma.

How to spot an atypical mole

At first glance, it can be tricky to see how an atypical mole differs from a normal mole. Below are some warning signs to watch for.

The ABCDE warning signs

The first five letters of the alphabet can be used as a guide to the warning signs for atypical moles and melanoma.

A is for Asymmetry. If you draw a line through the middle of the lesion, the two halves don’t match, so it looks different from a round and symmetrical common mole.

B is for Border. Borders tend to be uneven and may have scalloped or notched edges, while common moles tend to have more smooth and even borders.

C is for Color. Varied shades of brown, tan, red or black may be the first sign of an atypical mole or early melanoma. Common moles usually are a single shade of brown.

D is for Diameter and Dark. Atypical moles tend to be darker and grow larger than common moles, generally to at least the size of a pencil eraser (about 6 mm, or ¼ inch in diameter). However, they may also be smaller. No matter the size, it’s best to spot them as early as possible.

E is for Evolving. Any change in size, shape, color, elevation or another trait, or a new symptom such as bleeding, itching or crusting, may be a warning sign.

When in doubt, check it out: Your dermatologist will determine whether your pigmented lesion is an atypical mole or a melanoma, and provide you with detailed information about next steps.

Images: What to watch for

picture atypical mole

Atypical mole with asymmetry, border irregularity and multiple shades of brown.

atypical mole

Atypical mole with asymmetry, border irregularity, color variations and diameter greater than ¼ inch

Dysplastic nevus lowerback man

Atypical mole on lower back. Close-up of mole (on right) shows asymmetry, color variegation and border irregularity.

Please note: Since not all atypical moles have the same appearance, these photos serve as a general reference for what they can look like. If you develop a spot that raises suspicion, schedule an appointment with your dermatologist.

What causes atypical moles?

Scientists and researchers are still working on understanding what causes atypical moles. The reason they develop is believed to be a combination of genetic and environmental factors.

Atypical mole syndrome

People with atypical mole syndrome are at especially high risk of developing melanoma. The syndrome is associated with the following three characteristics:

  • 100 or more moles
  • One or more moles 1/3 inch (8 mm) or larger in diameter
  • One or more atypical moles

If you have hereditary risk factors for melanoma as well as many atypical moles, you may be classified as having Familial Atypical Multiple Mole Melanoma Syndrome (FAMMM), putting you at even greater risk for developing melanoma.

What is the treatment for atypical moles?

If you have one or more atypical moles, talk to your dermatologist about an appropriate surveillance program and whether or not any moles need a biopsy to ensure they are not melanomas. The more abnormal features moles have, the riskier they are. Frequent monitoring of these moles is especially crucial, so that if a melanoma arises, it can be detected and treated as early as possible.  

If your doctor identifies a mole as suspicious, or if new moles appear after age 40, you may need a biopsy.

What you can do

Know your skin: If you have atypical moles, FAMMM or other melanoma risk factors, perform monthly self-checks and visit your dermatologist regularly (at least once a year) for thorough head-to-toe skin exams. Talk to your doctor at length about self-monitoring steps you need to take. Advise family members to do the same.

Be on the lookout: See your dermatologist if you notice any of the ABCDE melanoma warning signs or any of the following changes on your skin:

  • Itching, bleeding, crusting, oozing or swelling of a skin lesion
  • Changes in color, size, shape, texture or elevation of a skin lesion
  • Pain

Protect against UV rays: You can reduce the skin cancer risk posed by UV-radiation by taking simple protective measures. Safeguard your skin against the sun every day, even when it’s cloudy. Avoid indoor tanning entirely.  Get the details on how to make healthy skin a way of life: Your Daily Sun Protection Guide.

Reviewed by:
Adele Haimovic, MD
Jesse M. Lewin, MD

Last reviewed: May 2019

Sun & Skin News

Ask the Expert: Is It Normal to Get New Moles in Your 30s?

Ask the Expert: Painful Moles

More Than Moles: When Melanoma Doesn’t Look Like You Think It Should