Myth or Fact: Busting Common Misconceptions About Rare Melanomas

When most people think of melanoma, they picture a dark, irregular mole on skin that has seen too much sun. That image is accurate for many cases, but it can also cause people to overlook the less common ways melanoma appears.

Ashley Steffens, M.D., FAAD, a dermatologist on the Melanoma Research Alliance (MRA) Leadership Council, explained that melanoma isn’t limited to sun-exposed skin.

“Melanoma can develop on the bottoms of your feet, on the palms of your hands, in the eye, in the mouth, and even other mucosal surfaces like your genitals or your rectum,” she said.

Cancers the Sun Doesn’t Cause

According to Steffens, about 10% of melanomas develop in areas that aren’t exposed to the sun, and these cancers aren’t caused by sun exposure at all. Daily sunscreen remains an important part of protecting your skin, but it can’t prevent every type of melanoma.

Melanoma can also form in any part of the eye. Steffens said eye melanoma is more common in people between about ages 50 and 70 and in those who freckle easily.

Warning Signs That Are Easy to Miss

People with darker skin tones can develop melanoma too. In these patients, it more often appears as a dark streak in a nail or a dark spot on the palms or soles of the feet.

A dark band under a nail isn’t automatically cause for alarm.

“Not every dark band in a nail is going to be melanoma,” Steffens said.

But some features raise concern. These include a streak on a thumbnail or toenail, one that covers more than 40% of the nail’s width, or one that is getting darker or changing.

Color can be misleading as well. Steffens said about 2% to 8% of melanomas are amelanotic, meaning they lack the typical brown or black pigment.

“They can be pink, they can be red, or they can even be skin toned,” she said.

Why Rare Melanomas Are Treated Differently

These rare forms often call for a different treatment approach. Because they tend to appear in places such as the eye, nails or mucosal surfaces, surgery can be more complex. They are also driven by different genetic mutations than common skin melanoma.

“Oftentimes, the type of immunotherapy that we’re using for cutaneous melanoma is not going to work for those rare subsets of melanoma,” Steffens said.

Reducing Risk and Advancing Research

For skin melanoma, avoiding indoor tanning is one of the clearest ways to lower risk. Steffens said tanning beds raise melanoma risk by about 15% to 27% overall. People who start tanning before age 35 are two to three times more likely to develop the disease, and the risk grows with each additional session.

Patients can also help researchers learn more about rare melanomas. Steffens said registries such as MRA’s rare melanoma registry collect real-world data directly from patients, helping close gaps in what experts know about these less common cancers.