“Organ: a collection of tissues that structurally form a functional unit specialized to perform a particular function.” There are 78 (or 79) organs in the human body. Skin is the largest one.
In 2015 a gastroenterologist invented a high magnification attachment to his endoscope (a probe-based confocal laser endomicroscopy – pCLE) that provided real-time histologic (cellular level) imaging of human tissues to inspect his patient’s gall bladder, bile ducts, and liver for any spread of cancer cells. He was amazed to see a matrix network of fluid-filled spaces interlacing throughout the liver. He sent pictures of the liver matrix to a premier liver pathologist who promptly responded, “We see that all the time in our liver slides. It is an artifact of the tissue preparation used to make the slide.” But, the gastroenterologist rejoined , “This is not a prepared tissue slide. This is a highly magnified picture of a part of the liver in a living patient.”
Three years later they published an article revealing their discovery of this fluid-filled lacy matrix, speculated that it connected to other organs throughout the body, categorized it as an organ, and called it “the interstitium” –
“In sum, we describe the anatomy and histology of a previously unrecognized, though widespread, macroscopic, fluid-filled space within and between tissues, a novel expansion and specification of the concept of the human interstitium. This new method of looking at living tissue lets researchers see these spaces filled. The fact that they’re connected raises the possibility that sampling the fluid in those spaces could help experts examine the spread of diseases.” (Sci Rep 2018*)
“This new ‘organ’ — it’s not officially recognized as one yet –is found in tissue from the lungs and aorta, the digestive tract and bladder, in the skin, and in many other spots . (WebMD)
The discovery had immediate implications for our concepts of human anatomy, the metastasis of cancer cells, communications between the gut and brain, and even a possible explanation of why some victims of severe trauma feel like “my whole body aches”. Practitioners of Eastern Medicine sharing a panel with these two researchers voiced no surprise at the matrix’s existence, “Our acupuncture practitioners have been using merdian points for needle placement for centuries, and they probably coincide with such a connective matrix.”
The skeptical comments from anatomy experts and pathologists about this “new organ” discovered by clinical practitioners were immediate: “The claims that the mesentery and interstitium are organs come from medical practitioners, not from anatomical scientists. Although both of these anatomical entities are important in the functioning of the body, neither satisfies the requirements that an organ be composed of two or more tissues and perform a special function. Alas, it appears to be much ado about nothing.” (Clin. Anat. 31:648-649, 2018)
“The paper presents an interesting description of a possible novel microanatomic structure of ‘pre-lymphatic’ or ‘interstitial’ spaces in normal tissues, which may play a role in normal function as well as tumor metasasis”, but cautions that the findings are limited to a fairly small number of patients . Overall, the work opens the door to additional study—in the hands of another group, as well as studying pCLE in other tissues—rather than being definitive”.
These last quotes are great examples of the scientific process at work, as well as of medical territory loyalty or “turf battles” . When a blockbuster discovery finds its way into the medical literature the common response is often “The sample was too small”, “It may be true, but other researchers need to confirm it”, and “Of course we need further studies.” Thank God for the scientific method. It insures that as more data is gathered the consensus of the truth will adjust.
The clinical practice world is divided into “innovators, early adopters, and late adopters”. The mantra of sincere and wise practitioners is that “you don’t want to be the first, or the last, to adopt a new innovation”; be it a new technology, a new technique, or a new drug. Having voiced that note of caution, I must admit that I think that the interstitium organ is an exciting, and possibly a unifying, concept that may well advance our management of both health and diseases in the future. TBD
Reference:
*Benias, Petros C.; Wells, Rebecca G.; Sackey-Aboagye, Bridget; Klavan, Heather; Reidy, Jason; Buonocore, Darren; Miranda, Markus; Kornacki, Susan; Wayne, Michael (2018-03-27). “Structure and Distribution of an Unrecognized Interstitium in Human Tissues”. Scientific Reports. 8 (1): 4947.
HUB's LIST of medical fun facts 