Melanoma Vs. Mole: How to Tell a Mole from Melanoma

Medically Reviewed By Joan Paul, MD, MPH, DTMH
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Almost everyone has moles on their skin, and they are usually harmless. However, some moles can become cancerous, and dangerous skin cancers can also resemble moles. This article looks at the differences between moles and melanomas. Read on to learn more and when to contact a doctor.

How is a mole different from melanoma?

A woman with several moles on her face
Lisa Vlasenko/Getty Images

Moles develop when cells called melanocytes cluster together. Melanocytes produce melanin, which is the pigment that gives skin its color. Moles are usually round and brown in color and can be flat or slightly raised.

Melanoma is a rare but dangerous form of skin cancer that also begins in melanocytes. Melanoma can develop in a mole and may resemble a mole.

Moles that may be melanomas are referred to as “atypical” moles and have certain identifying characteristics.

Learn more about atypical moles.

How do you identify an atypical mole?

Doctors use a few easy-to-remember strategies to help identify atypical moles that may require examination. One approach is the ABCDE rule, which stands for:

  • Asymmetry: The mole or brown spot has an irregular shape or mismatched parts.
  • Border: The spot has an irregular or jagged outline.
  • Color: The spot has uneven color or color changes.
  • Diameter: The spot is larger than the diameter of a pea or pencil eraser.
  • Evolving: The spot has changed over several weeks or months.

According to the Skin Cancer Foundation, moles that are 6 millimeters or more in diameter are more likely to be melanoma. Additionally, moles that bleed spontaneously or bleed without being scratched are characteristic of skin cancer.

Another way to check your skin is to look for “ugly duckling” moles. These moles are noticeably different from others on your body. Compared to other moles, atypical moles may be:

  • lighter or darker in color
  • larger or smaller
  • in an area of your body where there are no other moles

Up to 20 to 30% of melanomas develop in existing moles. However, the majority develop on other areas of the skin.

Does having atypical moles put you at greater risk for melanoma?

Atypical moles carry a higher risk of melanoma. Having a lot of moles also increases your risk. Most people have anywhere from 10 to 40 moles by the time they are adults. Moles usually change slowly over time, becoming lighter in color and more raised.

Having more than 50 moles significantly increases your risk of melanoma.

Melanoma is a dangerous type of cancer. However, it is usually treatable when detected early. Talk with your doctor about how to monitor your moles and how often you should have them checked.

Learn more about the outlook for melanoma.

Summary

Everyone has moles. However, an atypical mole may be an indication of melanoma, the most serious form of skin cancer. Contact your doctor or dermatologist if you notice a mole that:

  • grows larger over time
  • changes color
  • has an irregular border
  • looks different than other moles

Melanoma is treatable when detected early. However, it can be life threatening if it spreads to other areas of your body.

You can watch for signs of melanoma by performing regular skin checks. Talk with your doctor about how often to check your skin and what signs to look for.

Learn more about the ABCDEs of melanoma.

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Medical Reviewer: Joan Paul, MD, MPH, DTMH
Last Review Date: 2022 Nov 29
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