Mom credits TikTok video for cancer diagnosis after spotting strange nail marking

Lauren Koltcz, 45, from North Royalton, Ohio, noticed a brown line on her left thumbnail, but thought it was caused by a vitamin deficiency.

When the brown line became thicker, the mother of two spoke to her nurse practitioner, who said it could be a fungal infection.

"I put some fungal medication on my thumb, but it didn't do anything," said Koltcz, as the news agency also reported.

Then, in Feb. 2025, she noticed the line spreading across her nail.

"I started researching online and found some TikTok videos from dermatologists," she recalled.

Koltcz booked an appointment at Cleveland Clinic, where doctors took a biopsy of the brown area.

The next day, she got a call from her doctor, Alison Vidimos, M.D., who said they needed to do a biopsy.

"I was concerned because the pigmentation on her nail was very dark, there were different shades of brown, and the spot was wider than 3 millimeters," said Vidimos, who is chairman emeritus of Cleveland Clinic's Department of Dermatology.

The biopsy results came back four days later.

"I just couldn't believe it. Everybody knows someone who's had cancer, and now I was one of them," Koltcz said.

Subungual melanoma (nail melanoma) is a serious and rare type of skin cancer, accounting for 0.7% to 3.5% of all melanomas worldwide, according to Cleveland Clinic.

"When this type of cancer is caught early, there's over a 95% survival rate," Vidimos said in a press release from Cleveland Clinic. "But if it's neglected and not diagnosed at an early stage, it can spread to the lymph nodes and make treatment more challenging."

Nail melanomas are often diagnosed late, according to the doctor, because people don't think about checking their nails.

Prompt surgery removed Koltcz's cancer and some of the tissue around the area to ensure that no cancer cells remained.

"I just kept thinking, 'How lucky am I that I caught it in time and had such great doctors to treat it?'"