Interstitium: Newly Discovered Organ of the Human Body?

Even though medical science had known its existence for decades, does the latest research designating the interstitium as an organ of the human body valid?

By: Ringo Bones 

Researchers studying the structure and distribution of spaces in the human body have recently discovered a structure in the human body that could represent a newfound human organ and this organ just might be the biggest organ in our body. The latest study was published in the journal Science Reports back in Tuesday, March 27, 2018. Anatomists have since known the existence of the interstitium for years as the widespread fluid-filled spaces within and between tissues all over our body, although not all experts are convinced of the status of the interstitium as a bona fide human organ. 

Dr. Neil Theise, professor of pathology at NYU Langone Health in New York who was a senior co-author of the study says that “I think it’s bigger than the skin.” “The skin, comprising roughly 16-percent of your body mass is thought to be your largest organ, as for the interstitium, my estimate is that 20-percent of the volume of the body is this, which is equivalent to about 10-liters in a young adult.”

For the study, Dr. Theise and his colleagues used a powerful microscope with a technique known as confocal laser endomicroscopy to examine and analyze healthy living tissue samples from human bile ducts. The samples were taken from 13 patients undergoing pancreatic surgeries at Mount Sinai Beth Israel in New York. The samples were infused with a fluorescent liquid, allowing the researchers to see every detail. They wrote in the study that they observed spaces where fluid accumulates. Those spaces appeared to be pre-lymphatic, meaning they appeared to drain into lymph nodes. 

Traditionally, when such tissue samples are examined under a microscope, the tissues are dehydrated and look like dense layers, Dr. Theise said. So the interstitium could have gone previously unnoticed because its structure was collapsed due to dehydration every time tissue samples were subjected to microscopic examination. Since its discovery and designation as a possible newly-discovered human organ, interstitium is now under scrutiny on whether it might play a role and help us understand on how cancer spreads in our body.