|
|
 |
|
EDITORIAL |
|
Year : 2021 | Volume
: 70
| Issue : 1 | Page : 1-2 |
|
Discovery of new organs in human throat: The tubarial salivary glands
Vishram Singh1, Krishna Chaitanya Reddy2
1 Department of Anatomy, Kasturba Medical College, Mangalore, MAHE, Karnataka, India 2 Department of Anatomy, Kamineni Academy of Medical Sciences and Research Center, L. B Nagar, Hyderabad, Telangana, India
Date of Submission | 01-Nov-2020 |
Date of Acceptance | 02-Mar-2021 |
Date of Web Publication | 07-Apr-2021 |
Correspondence Address: Prof. Vishram Singh OC-5/103, 1st Floor, Orange County Society, Ahinsa Khand-I, Indirapuram, Ghaziabad, Delhi-NCR - 201 014, Uttar Pradesh India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/jasi.jasi_240_20
How to cite this article: Singh V, Reddy KC. Discovery of new organs in human throat: The tubarial salivary glands. J Anat Soc India 2021;70:1-2 |
“Scientists discover new human salivary glands” was the title of the article which hogged the limelight of most medical journal bulletins and newsletters on October 16, 2020.
According to the classical description in the textbooks of anatomy, there are three pairs of large salivary glands, namely parotid around the ears, submandibular below the mandible, and sublingual under the tongue.[1],[2] In addition to these glands, there are a number of minor salivary glands located in the mucosa of the oral cavity and named as lingual, labial, buccal, and palatine glands concurrent to their location. These glands are made up of serous, mucous, or seromucous acini and produce saliva. The saliva is poured into the oral cavity to help in mastication, digestion, tasting, swallowing, and dental hygiene.
It is worth mentioning that in addition to the salivary glands mentioned above, there are a number of discrete seromucous glands located in the mucosa of various parts of the aerogastric tract for the purpose of lubrication, protection, etc., The mucosa around the openings of the auditory tubes also contains discrete microscope seromucous glands for the lubrication of mucosa around the tubal openings. However, a large pair of new salivary glands was reported to be present in the human throat by the scientists from the Netherlands Cancer Institute (NCI) which was never noticed earlier.[3]
The scientists from NCI while doing a routine screening of 100 prostate cancer patients using prostatic-specific membrane antigen (PSMA) positron-emission tomography/computed tomography scan accidentally found the presence of large masses of glandular tissue in human nasopharynx in all patients. It was located above the torus tubarius, an elevation produced by a cartilage guarding the opening of auditory tube.
The scans of all the 100 patients clearly showed the PSMA-positive area (shinning yellow-like gold) above torus tubarius on either side in the region of the nasopharynx [Figure 1]a. This area extended from the skull base above to downward along the posterolateral wall of the pharynx [Figure 1]b. | Figure 1: [3] Prostatic-specific membrane antigen positron-emission tomography/computed tomography scan of head-and-neck region. The slices at the level of torus tubarius in the nasopharynx showing an orange signal at the site of salivary tissues expressing prostatic-specific membrane antigen. (a) Coronal slice showing bilateral presence of tubarial salivary glands. (b) Sagittal slice showing unilateral presence of tubarious salivary glands
Click here to view |
The glands were characterized by performing histological and histochemical examinations. The tissue was obtained from freshly donated dead bodies.
The three-dimensional reconstruction of histology slides showed salivary tissue in newly discovered glands (in yellow) and ducts in blue. These glands consisted of serous and mucous acini. The number of mucous acini was much more than serous acini similar to that of the sublingual salivary gland. The cells showed the cytoplasmic expression of PSMA. The ducts of these glands were opening in the posterolateral pharyngeal wall.
On an average, they are about 4 cm (1.5 inches) long. These glands were categorized as seromucous glands with ducts by histological histochemical studies. According to Woulter Vogel, co-author and radiation oncologist at NIC, the radioactive tracer used in this technique not only binds with the cells of prostate glands but also binds well with PSMA of cells of salivary glands.[4]
The above finding showed that the glands are part of the salivary system, thus forming the fourth pair of major salivary glands.[5],[6],[7] The scientists therefore named them as tubarial salivary glands. The secretions of these glands are poured onto the dorsolateral wall of the nasopharynx and lubricate and moisten the upper part throat located behind the nose (nasopharynx) and behind the mouth (oropharynx).
It is a bit surprising that these macroscopic glands were left unnoticed by anatomists, histologists, ear, nose, and throat surgeons, and histopathologists so far long.
Since, the salivary glands both major and minor pour their secretions into the oral cavity where it mixes up with food during mastication to help in digestion and swallowing of food bolus. Therefore, according to our opinion instead of calling these glands tubarial salivary glands, they should be simply named as tubarial glands.
The sparing of these glands during radiotherapy of head-and-neck cancer patients will relieve them from common posttherapy symptoms such as dryness of the mouth (xerostomia) and difficulty in swallowing (dysphagia).
References | |  |
1. | Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41 st ed. London, UK:Elsevier; 2015. |
2. | Moore KL, Agur AM, Dalley AF. Clinically Oriented Anatomy. 7 th ed. Philadelphia, Pennsylvania, United States: Lippincot Williams and Wilkins; 2018. |
3. | Valstar MH, de Bakker BS, Steenbakkers RJ, de Jong KH, Smit LA, Klein Nulent TJ, et al. The tubarial salivary glands: A potential new organ at risk for radiotherapy. Radiother Oncol 2021;154:292-8. |
4. | Klein Nulent TJ, Valstar MH, de Keizer B, Willems SM, Smit LA, Al-Mamgani A, et al. Physiologic distribution of PSMA-ligand in salivary glands and seromucous glands of the head and neck on PET/CT. Oral Surg Oral Med Oral Pathol Oral Radiol 2018;125:478-86. |
5. | Tos M. Mucous glands in the developing human rhinopharynx. Laryngoscope 1977;87:987-95. |
6. | Richardson MS. Non-neoplastic lesions of salivary glands. In: Thomson I, editor. Head and Neck Pathology. 2 nd ed. Woodland Hills, CA:Elsevier Saunders; 2013. p. 228. |
7. | Berger G. Eustachian tube submucosal glands in normal and pathological temporal bones. J Laryngol Otol 1993;107:1099-105. |
[Figure 1]
|