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 Center, David Carr-Locke and Petros Benias, found something unexpected while using the high-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 dryly in the journal Scientific Reports. And then the mystery deepened. The doctors showed the images to a pathologist, Neil Theise, who used a thinly sliced fleck of tissue removed from the patient to prepare the kind of glass slides scientists have been peering at with microscopes for centuries.
But the novel layer of tissue simply wasn't there - or at least it wasn't visible. Sacha Loiseau, founder and director of Mauna Kea Technologies, which made the camera-equipped probe that had revealed the phantom tissue, explained why. "The classic microscope on a lab bench magnifies dead tissue from a biopsy that has been dehydrated and treated with chemicals," he told AFP. The meshwork of liquid bubbles visible in the patient's body, in other words, had pancaked in the slides like a collapsed building, leaving hardly a trace.