I thought I had a ‘bruise’ on my nail — it turned out to be deadly cancer

She hit the nail on the head.

A manicurist in Scotland is being lauded for spotting a thin brown streak under a client’s nail — which led to a melanoma diagnosis.

Stacey Boss, 32, said she had shrugged off the mark on her right thumbnail for a while, until her nail tech discovered it in November 2019 and refused her a manicure, urging her to go to the doctor instead.

“I was very confused,” the record label owner admitted to Kennedy News. “I didn’t know anything about how melanoma skin cancer could be in a nail bed. It was mind-boggling.”

She initially believed it was a bruise under her fake nails.

“I’d just gotten used to it, and it wasn’t until someone pointed it out that it was a big, shocking moment,” she explained.

The mom of one visited her primary care doctor before being referred to a dermatologist, who diagnosed her with a subungual melanoma, a rare kind of skin cancer found under the nail.

The condition can be treatable when it’s found early, according to The American Academy of Dermatology Association, but a melanoma can be fatal if diagnosed too late.

Melanoma of the nail often presents itself, according to the dermatology association, as a dark streak in the nail bed, a split nail, a lifted nail or a bump under the nail — symptoms Boss said she experienced.

“It was like a streak. It was like someone had marked my nail with a permanent marker from the cuticle to the top,” Boss described.

She said it kept growing upward on her thumbnail.

“It was thin and skinny and almost as if someone had dented a mark on it. By the end it looked like a smiley face due to the shadow of the line, the dent and the way the cuticle grows,” she added.

In March, Boss had her nail and part of the bone removed, undergoing a biopsy of the nail bed.

There were some delays in her final diagnosis due to the coronavirus pandemic, she explained.

She is facing more tests to make sure the melanoma hasn’t spread to other parts of her body, like the lymph nodes.

She described the removal as a “relief,” admitting she felt like something had been wrong with her even before she got the diagnosis.

“I had anxiety, my whole body was changing, the line was never going away, it was always there,” Boss recalled.

However, there is a bit of silver lining to all of this — the music fan claims she gets a discount on her shellac French manicures because she has one less fingernail.

She is also hoping to raise awareness about this type of melanoma, urging others to take notice to subtle body changes — especially to their nails.

“The nail technician possibly saved my life, she’s well-trained and was very aware, more than me,” Boss said.

Boss isn’t the only person to receive this diagnosis — in 2019, a Chicago beauty queen revealed a similar discovery.

Karolina Jasko said she had noticed a thin black line, also on her thumbnail.

She went to the doctor for an unrelated infection, and a biopsy was ordered.

Her entire nail bed was removed. A skin graft taken from her groin was used to cover the finger.