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Moles & melanoma: When do I need to worry?

July 05, 2018 | UCI Health
doctor inspecting mole

Nearly every adult has a few moles. Fair-skinned people may have as many as 40 on their bodies. Most of these are nothing to worry about.

“Yes, a common mole can turn into melanoma, but that’s very rare,” says Dr. Maki Yamamoto, a surgical oncologist with the Melanoma Center at UC Irvine Chao Family Comprehensive Cancer Center

Common moles can be pink, tan or brown spots, aggregations of pigmented cells that are either round or oval in shape and have a smooth surface. But it’s important to keep an eye out for atypical moles that may put you at higher risk for melanoma, she says.

Skin cancer is by far the most common U.S. cancer and it will affect one in five people in their lifetimes. It is even more prevalent in sunny Southern California. Melanoma accounts for only 1 percent of all skin cancers. But it is the most deadly because it is aggressive and has a higher propensity to spread to lymph nodes or other organs than the more common basal- and squamous-cell carcinomas.

Live Well asks Yamamoto, an assistant professor with UCI School of Medicine’s Department of Surgery, what people need to know about moles and melanoma.

What is an atypical mole?

Atypical moles are often larger than the head of a pencil eraser and oddly shaped. They may also be more than one color. Sometimes it can be difficult to tell the difference between a benign atypical mole and a melanoma.

How do I recognize a melanoma?

Look for signs such as asymmetry, irregular border, varied color, enlarged diameter and a changing mole or lesion. We refer to these signs as the ABCDEs.

  • Asymmetry: The shape of one half does not match the other half.
  • Border that is irregular: The edges are often ragged, notched or blurred in outline. The pigment may spread into the surrounding skin.
  • Color that is uneven: Shades of black, brown and tan may be present. Areas of white, gray, red, pink or blue may also be seen.
  • Diameter: There is a change in size, usually an increase. The larger the mole, the greater the chance of malignancy.
  • Evolving: The mole has changed over the past few weeks or months.

Where on the body are melanomas usually found?

They can be anywhere, but as we get older, they have a propensity to be on sun-exposed areas such as the head/neck and trunk.

Can nicking or scratching a mole cause melanoma?

No. But easy bleeding from relatively little trauma can be a sign of melanoma.

Are there other warning signs?

Yes. An atypical mole that is itching, painful, swelling, crusting or oozing should be checked immediately by a dermatologist or other physician experienced with skin disorders.

How do doctors test for melanoma?

Sometimes cancer can be detected simply by looking at your skin, but the only way to accurately diagnose melanoma is with a biopsy.

Should I consider having moles removed?

If your moles fit the criteria above (see ABCDEs), then yes, absolutely.

What is the treatment for melanoma?

Surgery is the usual treatment for early-stage melanoma. We use immunotherapy for late-stage melanoma and metastatic disease, meaning it has spread to other parts of the body.

What can I do to prevent melanoma and other skin cancers?

    • Protect your skin from the sun’s ultraviolet rays by using sunscreen with a protection factor of at least 30 SPF.
    • If you are in the sun, reapply sunblock every two hours, or whenever you come out of a pool or the ocean.
    • Wear hats that shield your face and scalp.
    • Cover your arms and legs with long sleeves and long pants.
    • NO tanning beds!

Check your skin and existing moles often, following the ABCDEs. And see a doctor if you are concerned. Melanoma is highly treatable if caught in its earliest stages.

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