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Surprising places skin cancer can hide

By The Health News Team | May 19, 2021
A man has pain in his hand.

More Americans are diagnosed with skin cancer than all other cancers combined. Typically, it develops over time and is caused by a lifetime of cumulative exposure of ultraviolet (UV) radiation from the sun or tanning bed use. Genetics also play a role, including skin type and family history of cancer.

Most people know that hats, clothing and slathering on plenty of broad-spectrum sunscreen helps to protect their skin when they head outdoors. What most people may not know is that skin cancer can strike in some unexpected places, including areas of the body that don’t necessarily get much sun.

There are 3 general types of skin cancer: basal cell, squamous cell, and melanoma. The good news is that most skin cancers are curable when detected early, and many are preventable with good skin care. However, melanoma can be deadly if not caught in time, and can spread throughout the body if allowed to grow deeper into the skin.

“One out of 5 people will develop skin cancer during their lifetime,” says Dr. Mona Mofid, a board-certified dermatologist with Sharp Community Medical Group.

“Approximately 90% of basal and squamous cell skin cancers and 85% of melanoma cases are associated with exposure of ultraviolet radiation from the sun. It affects people of every age, ethnicity and gender,” she says.

“But it’s never too early, or too late, to make your skin a priority and start protecting it from damage.”

Here are 5 sneaky places where skin cancer can hide that Dr. Mofid recommends people should be checking.

1. Scalp. The scalp is one of the areas of the body that’s most exposed to the sun and a common site for skin cancer, especially in individuals who are bald or have thinning hair. People who notice any new, enlarging, bleeding or changing spots on their scalp should let their health care provider know. 

2. Eyes and eyelids. Pay attention to any new or growing spots around the eyelids or any dark spots in the colored iris around the pupil. Some people might experience blurry or spotty vision. UV light also contributes to cataracts, so it’s important to wear UV-protective sunglasses for protection.  

3. Under nails. Melanoma under a nail is rare, but it can happen. When it occurs, it’s usually on the thumb or big toe. It can start as a dark streak under the nail or discoloration at the cuticle, and is often mistaken for a bruise that’s not resolving.  

4. Soles of the feet and palms of hands. Think of all the times people expose their palms and soles to UV radiation, particularly when swimming. Check for any new or changing marks. Darker-skinned individuals are more at risk for melanoma in these areas; reggae artist Bob Marley died from melanoma on his toe. 

5. Under a tattoo. Some people get colorful tattoos to cover moles or birthmarks. The ink, however, makes it hard to spot skin cancer that might be growing underneath. So before showing off tattoos, cover them with plenty of sunscreen to protect the skin.

Dr. Mofid points out that most melanomas occur on the skin. However, there are also non-skin melanomas.

“A small percentage of these dangerous skin cancers can occur in other parts of the body. It can often be aggressive, difficult to treat, and accounts for about 4% of melanomas,” she says.

“Melanoma originates in the cells in the body that make melanin, called melanocytes. In development, melanocytes migrate from the neural crest to their final destination in the skin, but some are left behind in the spinal cord, mucous glands, and the urogenital tracts including the vaginal, vulvar, anal and rectal regions,” says Dr. Mofid.

“These can be difficult to diagnose and are usually discovered during medical evaluation for specific symptoms such as non-healing sores in the mouth; rectal or vaginal bleeding; or discoloration of the eyes or change of vision.”

President Jimmy Carter, at age 91, was diagnosed with melanoma that had spread to his liver and brain — without any skin lesions.

Dr. Mofid says, “New, innovative immunotherapy treatments that stimulate a person’s own immune system to recognize and destroy cancer cells are now being used to treat and cure advanced melanoma.”

Thanks to this type of treatment, President Carter is now 96 and continues to do well.
To protect your skin and reduce your skin cancer risk, Dr. Mofid offers these additional tips:

  • Cover up with clothing, including broad-brimmed hats, sunglasses and long sleeves when outdoors.

  • Wear sunscreen with broad-spectrum protection (UVA & UVB) that is SPF 30 or higher. When applying, don’t miss the tops and sides of your feet and between your toes.

  • Seek out shade and avoid long exposure in the sun during the hottest part of the day — between 10 am and 4 pm.

  • Avoid tanning beds.

  • When you make an appointment for an annual health checkup, include a skin exam as part of the visit.

  • Conduct your own self-skin exam on a monthly basis. If you see any suspicious spots, or changes in your skin, contact your doctor right away.

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