A university student was left in tears of happiness after recognising her guest lecturer from an experience that had nothing to do with university coursework.
Jacinda Holtsmark, 21, hopped on a Zoom call last Tuesday for her medical science class and came face-to-face with a man who saved her life two decades ago.
Unbeknown to everyone else on the Zoom call, the third-year University of Sydney student had crossed paths with Professor Ralph Cohen once before, when she was a baby with cancerous growths on both her kidneys.
Professor Cohen removed the cancer in surgery and it hasn't come back since.
"I was basically crying," Ms Holtsmark told news.com.au.
"One of the greatest gifts I could have received in my whole life was to thank him in person."
The cancer survivor interrupted the tutorial's question time to alert the professor of their shared past.
"Oh sorry, this is not actually a question just a full-circle moment. I'm quite shocked right now," Ms Holtsmark said in the video call.
"I believe you were actually my surgeon in 2001 and you operated on me for bilateral wilms tumour.
"I just wanted to say thank you so much."
Some class members laughed or gasped while Prof Cohen was left speechless for a moment.
"That's amazing, I'm completely floored, Jacinda," he eventually said.
"I'll turn my camera on but you won't recognise me because I was a baby," his former patient replied with a laugh.
"This is one of the great privileges of being a paediatric surgeon. You have the opportunity to do something for somebody later in life," he responded.
The doctor also said he had written a research paper on Ms Holtsmark's condition. She admitted she had read some of it.
Ms Holtsmark was barely a year old when her mother noticed a strange "bulge" on her right side.
Although many doctors turned them away with assurances that it was "nothing", one doctor eventually consented to an x-ray and discovered the worst - she had two cancerous tumours on both her kidneys.
Little Ms Holtsmark was fed through a tube and underwent chemotherapy at The Children's Hospital at Westmead.
There were fears that she would need a kidney transplant.
It was possible both kidneys would need to be entirely removed, and the human body needs at least one kidney to function.
However, Prof Cohen "did the surgery so well", according to Ms Holtsmark, that the transplant wasn't necessary.
He managed to keep enough of both her kidneys intact so that between them she had one working organ.
She spent one and a half years at the hospital in total for the cancer treatment.
After jumping onto her online tutorial on Tuesday, Ms Holtsmark thought the name 'Ralph Cohen' was familiar.
"I always heard of him, I knew of him, but I didn't really know his first name. I only knew him as Dr Cohen," she explained.
"I was texting my parents, asking them if it was him.
"As soon as my dad saw his (Prof Cohen's) face, he said 'I'd never forget that face, that's him'.
"My parents were crying.
"It's just insane how this happens."
Ms Holtsmark has ongoing check-ups at the hospital, and has come into contact with many of the staff who saved her life during her cancer procedures. However, not Prof Cohen.
"I never saw Prof Cohen after that surgery (and now) literally 20 years on, I was able to say thanks," she said.
She now studies a double degree of law and medical science at the University of Sydney, inspired by the lifesaving surgery, and hopes to become a cancer researcher one day.