As summer rolls in, people start focusing on sun protection, slathering on sunscreen and enjoying the outdoors. However, the sun isn't the only culprit when it comes to skin cancer. In fact, melanoma, one of the deadliest forms of skin cancer, often develops in areas that rarely see sunlight. One such form—acral melanoma—occurs in parts of the body that are not typically exposed to the sun, such as the palms, soles of the feet, and even under the nails.
Amy Jardon, a 40-year-old runner from Iowa, experienced a persistent itch between her toes that she initially thought was just a common irritation. But when a small black spot appeared, she decided to see a doctor. The initial diagnosis seemed harmless, but the doctor ordered a biopsy just to be cautious. Two weeks later, Amy received the unexpected news: she had melanoma.
Her diagnosis was acral melanoma, a subtype that affects between 2,000 and 3,000 Americans annually. While melanoma is most commonly linked to sun exposure, acral melanoma is different—its origins are not associated with ultraviolet (UV) rays. Instead, it typically arises in areas that don't get much sun, such as the soles of the feet, palms of the hands, or underneath the nails.
What makes acral melanoma even more concerning is how often it goes unnoticed. Amy's case is a rare one: because she sought medical attention early, her melanoma was caught at a treatable stage. Many other cases, however, are diagnosed too late, making the cancer much more dangerous. Acral melanoma tends to be harder to detect and is less responsive to current treatments compared to other types of melanoma, primarily due to its unique genetic mutations.
Scientists are still working to understand exactly what causes these melanomas. While exposure to UV rays is the primary cause of most skin cancers, acral melanoma appears to have a different genetic structure. Researchers have found that instead of a series of small mutations—like those caused by sun exposure—this type of melanoma features large, disruptive changes in DNA. Some genes are copied over and over, sometimes as many as 50 times. These mutations suggest that factors other than UV exposure could be at play, such as mechanical stress or injury. Studies have shown that acral melanoma is more common on pressure-bearing parts of the feet, such as the heel and ball. This could lead to inflammation, which in turn produces reactive oxygen species—molecules that can damage DNA and cause cancer.
Acral melanoma is especially tricky for people of color. Trena Brown, a 76-year-old woman from Baltimore, never thought she was at risk for melanoma. "I always thought melanoma was a white person's disease," she says. But after being diagnosed with acral melanoma three times since 2013, her perspective changed dramatically. Her first lesion appeared on her big toe, and after removal, it returned. Ultimately, she had to have her toe amputated. By 2016, the cancer had spread to her lungs. Trena underwent a grueling round of immunotherapy and now has regular MRIs to monitor her brain, where melanoma often spreads next.
Acral melanoma accounts for only 2-3% of melanoma cases in the U.S., but it is the most common type among people of African, Asian, and Hispanic descent. Although it is less common in white populations, no one is immune. Data shows that white people are just as susceptible to acral melanoma as people of other ethnic backgrounds.
Unfortunately, because this type of melanoma is rare, it often goes undiagnosed. Many people don’t even think to check the soles of their feet, the space between their toes, or under their nails for signs of cancer. By the time the melanoma is noticed, it may have already spread to other parts of the body. Early detection is crucial, and experts suggest paying attention to any suspicious marks or spots, especially in places that aren't typically exposed to the sun.
Treatment for acral melanoma usually involves surgery to remove the cancerous tissue, along with some surrounding healthy tissue to ensure that no cancerous cells remain. In advanced cases, doctors may turn to immunotherapy, chemotherapy, or targeted treatments aimed at the tumor’s specific genetic mutations. However, treatments specifically for acral melanoma have yet to be developed, and research into this rare form of melanoma is still in its early stages.
Despite these challenges, researchers are working to improve treatment options and raise awareness about acral melanoma. Part of the difficulty in studying this type of cancer lies in the fact that most research trials focus on UV-related melanomas, which are more common in white populations. As a result, there is a lack of data on acral melanoma. To address this, some advocacy groups are building patient registries and pushing for more research into the unique needs of people affected by acral melanoma.
The most effective defense against acral melanoma is awareness. People should regularly check their bodies for any new spots or changes, especially in areas that aren’t typically exposed to sunlight. Don’t assume that unusual spots on your feet or hands are harmless. If you notice something odd, don’t hesitate to get it checked by a healthcare professional. And if you are diagnosed with acral or mucosal melanoma, make sure to see a melanoma specialist who can offer the best possible treatment.
Amy Jardon’s early diagnosis serves as a reminder that early detection is key to surviving melanoma. Even though acral melanoma can be subtle and difficult to spot, it is not unbeatable. With increased awareness, improved research, and better treatment options, we can all do our part to fight this silent killer.