A woman was shocked to learn that a "cool streak" on her thumbnail which she had for years was actually a form of cancer.
Maria Sylvia, from the US said she first noticed a faint brown line on her thumb about 10 years ago but assuming it was "likely a mole" she didn't think anything of it.
After a friend prompted her to get a biopsy, the 25-year-old was diagnosed with subungual melanoma, a rare form of skin cancer that occurs under nails.
Now, Ms Sylvia urges anyone concerned about marks on their nail beds to see a dermatologist immediately.
"This is a very rare cancer, especially for my demographic but there’s no harm in going to see a doctor," she said.
'I thought it was a mole'
The 25-year-old has detailed the alarming discovery on TikTok, and like her, many were shocked to learn that her unusual marking was actually pretty serious.
In a series of videos, Ms Sylvia explained that she was "in and out of doctors all the time" because she used to be an athlete. But "no one really noticed it," she said.
Despite one doctor describing it as "odd" in 2014, she was told not to worry about it, she claims. Even after seeing a dermatologist.
"The diagnosis was that it was most likely a mole in the nail bed causing the pigmentation streak as the nail grew," Sylvia told Newsweek.
"The dermatologist felt there was less than a one per cent chance it could be subungual melanoma, so they didn't feel that a biopsy was warranted."
Now, some eight years later, Ms Sylvia says: "It’s very likely that this has been sitting for 10 years and it’s been cancerous for the last three."
"I didn’t really have any issue, I didn’t have any pain with it so I figured it was a mole because that’s what they told me... It was likely a mole in my nail bed," she said on TikTok.
Ms Sylvia said it was her friend who "really pushed me" to get it checked.
A fortunate ending: 'Super lucky'
Although the mark was left unchecked for so long, she was diagnosed with stage 0 subungual melanoma, she revealed, meaning the cancer had not spread.
"Everything looks good, it didn’t spread. I’m super lucky and very thankful," she said.
Ms Sylivia underwent surgery to remove the cancer and once successful, she underwent a skin graft using the skin from her arm to patch up her thumb.
"It doesn’t hurt too bad, pretty sensitive but most of the pain is pretty good, it’s tolerable," she said after her skin graft surgery.
As far as she knows, "my thumb should no longer have cancer," she told Newsweek.
"But I will have to continue seeing my oncologist and dermatologist every three months for the next two years, and then every six months for the remaining three years since I am now deemed at high risk for having skin cancer," she said
Doctor weighs in: 'Extremely rare'
After watching Ms Sylivia's video, Dr Karan Raj, a UK-based doctor who's taken TikTok by storm, revealed it's "pretty common" for people with darker skin to develop a brown line on their nail - and it's not always cancer.
There can be "lots of causes," including infection, medication side effects, trauma and blood clots. But it certainly is a sign of subungual melanoma, he said.
A brown stripe on the nail is "extremely rare" for people with melanoma. In fact, it happens in "about 1% of all melanoma cases," he said.
So while the unusual marking isn't always a sign of something serious, if you notice a rapid change in size, colour or shape, Dr Raj says to "go check it out."
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