The interstitium is a newly discovered part of the human anatomy and it may explain how cancer spreads

Thanks to a laser-equipped mini-microscope developed by a French start-up, scientists have discovered a previously undetected feature of the human anatomy that could help explain why some cancers spread so quickly.

Nobody was looking for the interstitium, as the new quasi-organ is called, because no one knew it was there, at least not in complex form revealed in a study published this week.

As with many breakthroughs in medicine and science, it was – to paraphrase Louis Pasteur’s oft-quoted dictum – a case of chance favouring the prepared.

In 2015, a pair of doctors at New York’s Beth Israel Medical Centre, David Carr-Locke and Petros Benias, found something unexpected while using the hi-tech endoscopic probe to look for signs of cancer on a patient’s bile duct.

There on a screen, clear as day, was a lattice-like layer of liquid-filled cavities that did not match anything found in the anatomy chapters of medical school textbooks.

“These have no obvious correlate to known structures,” they noted drily in the journal Scientific Reports.