by Cynthia M. Johnson, MA
Moles are spots on the skin where pigmented cells have clustered together. They often appear as light to dark brown spots on the skin. They can be flat or raised. They are benign (harmless) in most people.
Dysplastic nevi are atypical (not typical) moles. They can turn into a type of skin cancer called melanoma.
Moles develop from cells in the skin called melanocytes. Normally, these cells are evenly spread out. A mole happens when the cells form a cluster.
The risk of this problem is higher in people who have:
Most people will have benign moles that appear at birth through the teen years. Most adults have 10 to 40 moles.
Benign moles can appear anywhere on the body. They may be:
Signs that a mole may be atypical are:
When Should I Call My Doctor?
Call your doctor if you:
The doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the skin.
The mole may need to be tested. This can be done with a biopsy.
Benign moles do not need to be treated. Some people may have them removed if they are unsightly or get irritated.
Atypical moles may be watched for changes or removed. Atypical moles that are or may be cancerous can be removed with surgery. The mole tissue is examined under a microscope.
Not all moles can be prevented. The risk of some moles may be lowered with skin protection, such as:
American Academy of Dermatology
American Cancer Society
Canadian Dermatology Association
Common benign skin lesions. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/common-benign-skin-lesions. Accessed March 12, 2021.
Common moles, dysplastic nevi, and risk of melanoma. National Cancer Institute website. Available at: https://www.cancer.gov/types/skin/moles-fact-sheet. Accessed March 12, 2021. Accessed June 20, 2018.
Dysplastic nevus. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/dysplastic-nevus. Accessed March 12, 2021.
Moles. American Academy of Dermatology website. Available at: https://www.aad.org/public/diseases/bumps-and-growths/moles. Accessed March 12, 2021.
Perkins A, Duffy RL. Atypical moles: diagnosis and management. Am Fam Physician. 2015 Jun 1;91(11):762-777.
Sunscreen FAQs. American Academy of Dermatology website. Available at: https://www.aad.org/media/stats/prevention-and-care/sunscreen-faqs. Accessed March 12, 2021.
Last reviewed December 2020 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 03/12/2021