When Lee Spievack cried out in pain after slicing off his fingertip he had no idea he was about to find himself at the centre of a medical mystery that appeared to have more in common with Harry Potter than the British Medical Journal.
Rather than follow his doctor's advice and have a skin graft to cover what was left of his finger, the 68-year-old shopkeeper sprinkled the wound with a powdered extract of pig bladder.
Within four weeks, his finger had regained its original length and by the end of four months it was almost back to normal.
Now scientists in America believe the pig bladder "potion" may lead to an extraordinary breakthrough in regenerative medicine that could re-grow fingers, toes and limbs and even one day help replace damaged parts of hearts and spinal cords and heal wounds and burns with new skin instead of scar tissue.
He had been helping a customer with an engine on a model airplane when he accidentally put his finger too near the propeller and sliced off his fingertip, leaving just a bit of the nail bed.
The missing piece, about one centimeter long, was never found.
Up until the age of two humans can regrow fingertips, but doctors said he'd have to grow used to being without it.
However, Spievack's brother, Alan, a former Harvard surgeon, runs a company called ACell Inc. that makes an extract of pig bladder that had been used in the past to help horses re-grow ligaments.
At his brother's suggestion, Mr Spievack started applying the powder every two days. After four months, "it looked like my normal finger except it's a little hard, as if calloused, and there's a slight scar on the end," he said.