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Medical Author:

Gary W. Cole, MD, FAAD

Gary W. Cole, MD, FAAD

Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Moles facts
• What are moles?
• What causes moles, and what are risk factors for developing moles?
• What types of moles are there?
• What are liver spots or age spots?
• What are seborrheic keratoses?
• Who is more prone to getting moles?
• Does having more moles increase my chance of getting melanoma?
• Do moles ever disappear spontaneously?
• Which skin cancers look like moles?
• How can moles be prevented?
• How can moles be treated? What are different types of mole removal?
• Is there a blood test or X-ray to diagnose moles?
• Find a local Doctor in your town
• Moles Index

There are three basic types or groups of moles: regular, irregular, and cancerous. Irregular moles are also called atypical moles. Regular moles are typically benign and friendly. Regular moles are usually symmetrical, have regular borders, uniform color, and are about the size of a pencil eraser or smaller. Regular moles may be flat or raised. The presence of hair growing from a mole is unrelated to its cancer potential.

Irregular or atypical moles are usually asymmetrical, with irregular borders, multiple colors, and tend to be bigger than the size of a pencil eraser. Irregular moles are often flat or nearly flat. Having more than 20-25 irregular moles may increase the person's overall risk of developing melanoma. The presence of a giant congenital mole greater than approximately 8-10 inches in size also may confer an increased risk of melanoma. Irregular moles signal the potential for developing melanomas over time. Irregular moles themselves rarely turn into melanoma or cancer.

Cancerous moles like melanomas are highly irregular and have already become malignant. A small number of regular moles may potentially evolve and become irregular or cancerous over time. It is important to watch all moles closely for change or atypical features. Monthly skin self-examinations and at least annual full-body moles exams by a dermatologist are important in the early detection of abnormal moles and melanoma.

• A -- Asymmetrical
• B -- Irregular borders
• C -- Multiple colors
• D -- Diameter bigger than a pencil eraser
• E -- Evolving, changing, or new

Irregular moles can occur anywhere on the body but are most commonly located on sun-exposed skin, especially on the upper back and shoulders where people frequently get their most severe sunburns. The risk of melanoma is greater on sun-damaged skin like the shoulders, upper back, head, and neck. Ears are a particularly common site of atypical moles because of the difficulty in applying sunscreen and frequent sun exposure. Women have increased risks of atypical moles, particularly on the lower leg and calf. Any new or changing irregular mole on a woman's calf warrants immediate medical evaluation.