A study published in the journal Scientific Reports reveals the discovery of the largest organ of the human body: the interstitium. It is a fluid-filled structure circulating throughout the body. Hitherto invisible, the interstitium could be the origin of the spread of cancer through metastases.
Indeed, the interstitium is a network of compartmentalized tissues. These compartments, interconnected, look like bubbles and are filled with liquid. For researchers, it is the 80th organ of the human body, and by far the largest! It is found under the skin, along the digestive system, lungs, around the veins and arteries, in the bladder and between the muscles.
The interstitium would function as a damper that prevents the tissues of the organs and muscles from tearing. “This newly discovered network is the main source of lymph,” say the authors of the study. “A liquid that plays an important role in the body as it carries white blood cells, cells that help our body to defend against infections.”
Interstitium threatens our health
In addition to this “shield” function, the interstitium, which runs throughout the body, promote the spread of cancer. “This layer is a fluid highway in motion,” say the researchers. This open organ, made up of interconnections and present throughout the body, can “be easily traversed by invasive tumor cells,” they add. The configuration of this organ would therefore facilitate the spread of cancer via metastases.
“This discovery has the potential to drive dramatic advances in medicine, including the potential for direct interstitial fluid sampling to become a powerful diagnostic tool,” said Neil D. Theise, co-author of the study. This hypothesis must nevertheless be deepened.
However, Dr. Stéphane Vignes, head of lymphology at Congnacq-Jay Hospital in Paris, is more cautious: “It is possible, indeed, that this network, helps spread cancer, but I would be careful with this statement. Many factors can explain this spread, starting with the varying aggressiveness of cancer cells.”
New microscopy technologies have made this discovery possible. Thanks to confocal endomicroscopy, the researchers were able to observe the cells in vivo and thus see the fluid circulating in the tissues. “Once the team identified this new space in the bile duct images, they quickly spotted them throughout the body,” reports the NYU School of Medicine.