An eagle-eyed New York doctor spotted a cancerous lump on a woman’s throat as she appeared on a TV show — and may have saved her life by tracking her down hundreds of miles away, sources said Tuesday.

“Helping her was heartwarming and emotional,” Dr. Erich Voigt told The Post. “I’ve held back some tears.”

Voigt, an otolaryngologist at NYU Langone Health, was watching HGTV’s “Beachfront Bargain Hunt” in early May when he noticed the small bump on the left side of Nicole McGuinness’ throat, he said.

“I was relaxing after a day of work, watching beautiful beach houses and day-dreaming,” Voigt recalled. “But then I noticed the lump. It stood out — and I went from being relaxed to [thinking], gosh, she may have a medical problem.”.

Voigt, who has examined thousands of patients with similar symptoms, said the lump had a specific asymmetrical look and “way of moving under the skin” when she spoke that worried him. ​​

“I thought, I don’t think she knows she has this. I felt obliged and sort of guilty, like I should let her know,” he said. “I paused my TV and rewound it. I had to make a choice whether to ignore it or actively try to contact her.”

The doctor then launched a mission to find McGuinness via Facebook by posting a clip from the show, along with a hashtag, and enlisting his social media network to help track her down.

Voigt got in touch with McGuinness, a 32-year-old from Havelock, N​.C., ​two weeks later and told her to get ​a ​sonogram and a biopsy. She was then tested by a local doctor and learned she had thyroid cancer.

McGuiness, who is already a brain cancer survivor, is now undergoing treatment.

“It’s just a miracle, in my opinion, that he happened to see this on television,” the grateful woman told ABC News.

On Tuesday, she met the doctor in Manhattan while filming a segment for “Good Morning America.”

Voigt is now cautiously optimistic that she will beat cancer again.“With anything that’s found early and before symptoms, there’s a better chance of recovery,” he said.

The situation is an example of technology finally doing some good, he added.

“Social media can generate fake news and negative feelings — but this time it was used in a good and positive way,” he said. “It helped someone. It connected people.”