It’s been more than 2,000 years since Hippocrates first came up with the foundation of modern medicine, so you’d be forgiven for thinking doctors have identified all the organs in the human body already.
But in new research published Tuesday in the journal Scientific Reports, researchers at New York University’s School of Medicine announced they had discovered a brand new “organ” called the interstitium – and it may lead to insights about how to treat cancer.
For a long time, doctors thought the layers of cells under the skin and lining some organs were just dense collections of connective tissue.
Instead, the researchers found that those layers were actually vast networks of fluid-filled spaces, all held in place by strands of collagen and elastin (types of proteins that make body tissues stretchy or taut).
The organ’s use seems to be as a sort of “shock absorber” that protects the body’s tissues from tearing as organs go about their daily beating, pumping, and squeezing, the scientists wrote in a news release.
The researchers wrote that nobody ever knew about those spaces because scientists were accidentally collapsing those fluid-filled chambers when they took samples to look at under a microscope.
Normally, scientists slice thin samples of tissue and then dye them so they can be seen better. But when they do that, the scientists were causing the chambers of fluid to to “pancake, like the floors of a collapsed building,” the researchers wrote.
In this case, the scientists used a new technique that combined laser imaging with a super-tiny, camera-toting probe called an endoscope. They stumbled upon the interstitium by accident while trying to figure out whether a patient’s cancer had spread.
The organ’s role in the spread of cancer is a major question: The scientists say the little chambers form a “highway of moving fluid.” That highway can transport cells all throughout the body – and that includes cancer cells.
“Once they get in, it’s like they’re on a water slide,” the study’s co-author Neil Theise told New Scientist. “We have a new window on the mechanism of tumour spread.”
Theise wrote that the discovery of the organ could lead to new ways of detecting cancer or other diseases.
“This finding has potential to drive dramatic advances in medicine, including the possibility that the direct sampling of interstitial fluid may become a powerful diagnostic tool,” he wrote in a news release.
The discovery comes only a year or so after scientists reported the discovery of another organ called the mesentery, which was found to be a kind of fatty strip that helps hold the intestines in place.