The other spot was 0.65 millimeters in diameter — about the size of a needle tip — and had a slightly different pigment than a normal mole. So Witkowski looked at it through a microscope.

After noticing abnormal cells, Witkowski told Staats the mole was likely cancer.

Further tests confirmed Staats’s mole was melanoma, a dangerous skin cancer. Because Witkowski noticed the lesion early, he was able to remove it before the cancer spread.

Last week, Guinness World Records recognized Witkowski and his team of researchers for discovering the smallest known skin cancer spot.

“We want to share this knowledge with the next generation as this realm of health care begins to change — I think in a good way,” Witkowski, 36, told The Washington Post.

A Guinness World Records spokeswoman said this was its first record for the smallest skin cancer spot. Witkowski said the previous smallest spot diagnosed, which wasn’t recognized by Guinness, was 0.9 millimeters in diameter.

About 12 years ago, Staats said she noticed a spot under her right eye that burned. She visited a dermatologist, who told her there wasn’t an issue but advised her to keep inspecting the mole, Staats said. She continued to make dermatology appointments over the next four years, but then the burning — and her visits — stopped.

During the coronavirus pandemic, Staats said she became more focused on her health. Without commuting to her engineering job, she had more time to schedule medical checkups she’d postponed.

Witkowski and his wife, Joanna Ludzik, took over Oregon Health & Science’s skin imaging and technology center in October 2019. The dermatologists had previously worked in Italy and Poland, where they spent about $100,000 on a confocal microscope, which allows doctors to view cells underneath skin. The technology was not widely available in the United States, but they wanted their patients to have access to the same tools.

Witkowski used the microscope when Staats visited in July 2021. He also used a dermatoscope, a camera-like tool that inspects skin lesions, to check Staats’s moles. Witkowski determined that the spot that burned under Staats’s eye was benign. Then, he spotted the second mole.

Witkowski said some cancerous moles less than 5 millimeters in diameter go undetected. He said he routinely sees lesions about a millimeter in size, but Staats’s mole was hardly noticeable. Using the confocal microscope, Witkowski said he found bright and reflective cancerous cells on the mole.

“You’ll think I’m crazy, but I think this is the smallest skin cancer to date,” Witkowski recalled telling Staats.

When Staats returned to her Portland, Ore., home, she researched melanoma and came to believe Witkowski had saved her life. Melanoma is difficult to treat after it has spread, according to the Skin Cancer Foundation.

About two weeks later, a biopsy of Staats’s skin tissue confirmed she had melanoma. In August 2021, Staats had the spot surgically removed.

“What if it were one of those kinds that goes really fast, would I be in the middle of having cancer all over the place right now?” said Staats, who’s now 62. “I mean, that’s what I think of, but I try not to let my head go there.”

Staats said she has since changed her lifestyle, wearing hats, sunglasses and clothing that helps block ultraviolet rays. She returns to Witkowski twice each year for checkups.

Staats said she felt fortunate she could celebrate the world record with Witkowski and his team of researchers last week.

“I just was really lucky to be in the right place at the right time with the right technology,” she said. “I’m just a very lucky person.”