It was accidentally identified when examining prostate cancer patients with an advanced type of scan
It seems that the human body still has secrets that scientists, until now, had not discovered. Proof of this is that researchers in the Netherlands have found what appears to be a mysterious set of salivary glands hidden inside the human head.
This “unknown entity”, hidden from researchers for centuries, was identified by accident when examining prostate cancer patients with a type of advanced scanner called PSMA PET / CT.
This diagnostic tool, when combined with injections of radioactive glucose, highlights tumors in the body. But in this case, however, it showed something totally different, nested in the back of the nasopharynx.
New salivary glands
“People have three sets of large salivary glands, but not there,” explains radiation oncologist Wouter Vogel from the Netherlands Cancer Institute. “As far as we knew, the only salivary or mucous glands in the nasopharynx are microscopically small, and up to 1,000 are evenly spread out throughout the mucosa. So, imagine our surprise when we found these.”
“To our knowledge, this structure did not fit prior anatomical descriptions.”
The salivary glands are those that produce the saliva essential for the functioning of our digestive system, with the bulk of the fluid produced by the three main salivary glands, known as the parotid, submandibular and sublingual glands.
There are also approximately 1,000 minor salivary glands, located throughout the oral cavity and aerodigestive tract, but they are generally too small to be seen without a microscope.
The new discovery made by Vogel’s team is much larger, showing what appears to be a previously overlooked pair of glands, located behind the nose and above the roof of the mouth, near the center of the human head.
“The two new areas that lit up turned out to have other characteristics of salivary glands as well,” the first author of the study, the oral surgeon Matthijs Valstar of the University of Amsterdam (Netherlands), points to Science Alert. “We call them tubarial glands, referring to their anatomical location [above the torus tubarius].”
Thanks to technology
These tubal glands were seen on PSMA PET / CT scans of the 100 patients examined in the study and physical investigations of two cadavers also showed the mysterious bilateral structure, revealing macroscopically visible drainage duct openings into the nasopharyngeal wall.
“It was hypothesised that it could contain a large number of seromucous acini, with a physiological role for nasopharynx/oropharynx lubrication and swallowing”
“As far as we knew, the only salivary or mucous glands in the nasopharynx are microscopically small, and up to 1,000 are evenly spread out throughout the mucosa. So, imagine our surprise when we found these,” explain the researchers in their work, published in the scientific journal ‘Radiotherapy and Oncology‘.
“It was hypothesised that it could contain a large number of seromucous acini, with a physiological role for nasopharynx/oropharynx lubrication and swallowing,” they add.
Although the team admits that additional research will be needed in a larger and more diverse group to validate their findings, they argue that the discovery provides another goal to avoid during radiation treatments for cancer patients, as the salivary glands are highly susceptible to the damage from therapy.
Preliminary data, based on a retrospective analysis of 723 patients who underwent radiation treatment, appear to support the conclusion that radiation applied to the region of the tubal glands leads to further complications for patients.