Researchers appear to have discovered a new organ in humans (and presumably, in all mammals.)
The following has been adapted from “Newfound ‘organ’ had been missed by standard method for visualizing anatomy” (Press Release, NYU Langone Health/NYU School of Medicine)
Layers of the body – long thought to be dense, connective tissues – below the skin’s surface, lining the digestive tract, lungs and urinary systems, and surrounding arteries, veins, and the fascia between muscles – are instead interconnected, fluid-filled compartments.
This series of spaces may act like shock absorbers that keep tissues from tearing as organs, muscles, and vessels squeeze, pump, and pulse as part of daily function.
This layer is a highway of moving fluid – it may explain why cancer that invades it becomes much more likely to spread. Draining into the lymphatic system, the newfound network is the source of lymph, the fluid vital to the functioning of immune cells that generate inflammation. Furthermore, the cells that reside in the space, and collagen bundles they line, change with age, and may contribute to the wrinkling of skin, the stiffening of limbs, and the progression of fibrotic, sclerotic and inflammatory diseases.
The field has long known that more than half the fluid in the body resides within cells, and about a seventh inside the heart, blood vessels, lymph nodes, and lymph vessels. The remaining fluid is “interstitial,” and the current study is the first to define the interstitium as an organ in its own right, and as one of the largest of the body, say the authors.
No one saw these spaces before because of the medical field’s dependence on the examination of fixed tissue on microscope slides… Scientists prepare tissue this examination by treating it with chemicals, slicing it thinly, and dying it to highlight key features. The makes vivid details of cells – but drains away any fluid. The current research team found that the removal of fluid [causes this very thin organ] to pancake, like the floors of a collapsed building.
The study findings are based on newer technology called probe-based confocal laser endo-microscopy,… It offers a microscopic view of living tissues instead of fixed ones.
[In 2015] David Carr-Locke, MD, and Petros Benias, MD, saw something strange while probing a patient’s bile duct for cancer spread. It was a series of interconnected cavities in this submucosal tissue level that not match any known anatomy.
Faced with a mystery, the endoscopists walked the images into the office of their partnering pathologist in Theise. Strangely, when Theise made biopsy slides out of the same tissue, the reticular pattern found by endomicroscopy disappeared. The team would later confirm that very thin spaces seen in biopsy slides, traditionally dismissed as tears in the tissue, were instead the remnants of collapsed, previously fluid-filled compartments.
For the current study, the team collected tissue specimens of bile ducts during twelve cancer surgeries that were removing the pancreas and the bile duct. Minutes prior to clamping off blood flow to the target tissue, patients underwent confocal microscopy for live tissue imaging.
Once the team recognized this new space in images of bile ducts, they quickly recognized it throughout the body, wherever tissues moved or were compressed by force.
The other first study author was Rebecca Wells of the Perelman School of Medicine at the University of Pennsylvania, who determined that the mesh in the newfound sinus was comprised of collagen and elastin bundles.
How was this discovered?
Petros C. Benias, Rebecca G. Wells, Bridget Sackey-Aboagye, Heather Klavan, Jason Reidy, Darren Buonocore, Markus Miranda, Susan Kornacki, Michael Wayne, David L. Carr-Locke & Neil D. Theise
Scientific Reports, volume 8, Article number: 4947 (2018)
doi:10.1038/s41598-018-23062-6, Published online 27 March 2018