About Dysplastic Nevus

A dysplastic nevus (also known as an atypical mole) is an unusual mole that does not have the symmetric round or oval shape of a common mole. A dysplastic nevus is normally larger (wider than a pencil eraser), contains a mixture of colors from pink or red to tan or dark brown, and may contain an irregular edge.  Some are flat, but may be slightly scaly, or have a rough surface. People with many dysplastic nevi have an increased chance of developing melanoma, but most dysplastic nevi do not turn into melanoma and remain stable over the course of time.

Risk Factors for Dysplastic Nevi

Any area of the body may contain dysplastic nevi. Some are inherited, but areas exposed to the sun may commonly develop moles over time. If you have dysplastic nevi it is important to protect your skin from the sun and stay away from tanning beds. People with light colored hair or eyes and freckles are at highest risk for sun damage. Changes in a dysplastic nevus that is important to inform your dermatologist about include: color, size, shape, texture, and symptoms such as itching, bleeding, or pain.

Preventing Melanoma

People with many dysplastic nevi or a personal or family history of melanoma should be followed by a board certified dermatologist. Sometimes this necessitates seeing a dermatologist every three to six months. Discuss the frequency of needed visits with your dermatologist. Some doctors will use dermoscopy, a noninvasive hand held magnifier to view moles or take photos of moles at higher magnification during the skin examination to more easily identify changes suggestive of melanoma. Total body photography may also be suggested in patients with many moles to compare old and new.  

If changes are identified, your dermatologist may decide to remove the mole by performing a skin biopsy or excision. However, most people will not need to have dysplastic nevi removed, as removing all the moles on your skin will not prevent the development of melanoma. Your dermatologist will only remove a mole that has changed, has symptoms, or is new and different compared to other moles on your skin.  Cosmetic removal of dysplastic nevi can be performed, but may leave a scar in place of the mole or the mole may return over time.

Dysplastic nevi are classified in 3 groups depending on how abnormal they look under the microscope. Dysplastic nevi with histology of “mild dysplasia” are often just followed by annual skin checks; dysplastic nevi with histology of “moderate/severe dysplasia” are often treated with excision.