‘It’s rare and it’s scary.’ Dark spot on your fingernail could mean cancer

If you are staring at a dark spot under your fingernail, you may want to see a dermatologist. It could be a form of melanoma.

“It is rare, and it’s scary that it’s rare, because a lot of people would not think to check their nails,” said Lauren Koltcz, whom the Cleveland Clinic featured after doctors operated to cut out a malignancy under her fingernail as well as surrounding tissue to remove any remaining cancer cells.

Subungual melanoma, which appears under fingernails and toenails, is a rare but serious form of skin cancer that typically isn’t caused by sun exposure. It usually appears as a dark line or discoloration under the nail. This type of melanoma affects people of all races, ethnicities and ages. If caught early and the melanoma is just in the upper layer of the skin, the prognosis is better and treatment is less invasive.

Koltcz said she initially attributed the brown mark on her nail to a vitamin deficiency and dismissed it. Now she is grateful she saw a doctor and caught her melanoma early enough to be surgically removed.

Subungel is a type of acral lentiginous melanoma that develops in non-sun-exposed body areas, such as the palms and soles. “It’s more rare, but it’s also potentially more aggressive,” said Dr. Paul Benedetto, a dermatologist and Mohs surgeon with the Cleveland Clinic Florida.

“It’s not entirely clear if this form of melanoma is inherently more aggressive or diagnosed at later stages,” he said. “No one is really looking for them or clear on the signs they are seeing.”

Benedetto has several patients who arrive in his Coral Springs office each year with melanoma under their finger or toenails. He also has cases of acral lentiginous melanoma, noting that on the feet or hands, even a small brown dot can be skin cancer.

“That’s why you need a full skin check from head to toe in your birthday suit,” he said.

Dermatologists say regular screening is important to help prevent and detect all types of melanoma and skin cancer.

Miami Cancer Institute’s Skin Cancer Clinic can do a whole-body scan with the Vectra 3D, a machine that takes detailed images and creates a body map to allow experts to study and monitor lesions and other skin abnormalities and accurately assess changes over time. The Vectra can also take close-up dermoscopy photos of suspicious lesions for even more detailed monitoring and for detecting skin cancer at an early stage.

Generally, insurance does not cover the cost of Vectra 3D imaging, which runs about $595. Recent legislative efforts in Florida to require insurers to pay for annual skin cancer checks failed.

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