Page 145 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

The tubarial glands paper: A starting point. A reply to comments
tenfold between the parotid and sublingual gland and the uncontaminated crevicular fluid (formed by serum and locally generated materials) contains no amylase [14–16] . Therefore, in our opinion, the uninvestigated fluid composition argument to call the tubarial glands salivary glands does not seem to hold.
Second, Bikker and Vissink argue that the tubarial glands do not contribute to the oral fluid, but they do not provide evidence for this statement. In addition, one could question this criterium for calling the tubarial glands actual salivary glands. Functional and histological characteristics rather than location of the gland or its fluid, should determine whether it can be considered a salivary gland. However, we have been able to perform a simple in vivo pilot study (n = 1) in a healthy volunteer, in which 1 ml of blue dye in thickened slimy saline was put directly next to the tubarial gland on the cranial side of the soft palate. This subsequently led to staining of the pharyngeal wall, but also of the palatopharyngeal arch, which is the dorsal border of the oral cavity (Fig. 2). Based on this finding, one could say it is not unthinkable that the excreted fluid from the tubarial glands reaches the oral cavity. If this contribution to the oral cavity fluid is used as a criterium for saliva, the fluid from the tubarial glands might thus be considered as saliva.
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Figure 2: Torus tubarius (A). Thickened saline with blue dye applied right next to the tubarial gland area (B). Blue dye on the palatopharyngeal arch, which is part of the oral cavity (C).
Third, the authors of the letter mention the absence of a main excretory draining duct as an argument against the categorization as a major gland, but they at the same time admit that this is not really an argument, because part of the sublingual gland has similar ducts as the tubarial glands. The relativity of this argument was already discussed in the original paper. Additionally, the excretory duct openings of the tubarial glands are macroscopically visible as small holes filled with a secrete
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