Page 144 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

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Chapter 9
10]. The new techniques of PSMA PET/CT and 3D reconstruction of histological slides that were presented in the paper, opened a new perspective that did not fit previous anatomical descriptions. To our knowledge, there has not been a prior interpretation of the gland tissue in this area as a localized and organized macroscopic glandular structure, similar to one of the major salivary glands (the sublingual gland). Earlier contributions by colleagues to the knowledge of the embryology and anatomy of the nasopharynx fit into this new perspective, but in our opinion, it is not the other way around. Additionally, anatomical knowledge of the area had until now not been translated into clinical consequences, regarding the evaluation of the potential role as an OAR.
Therefore, this bilateral gland structure that we named “the tubarial glands” can be regarded as a potential OAR. Earlier, this realization led to our evaluation of toxicity in a cohort of 723 head and neck cancer patients, in which that theory was confirmed. As far as the anatomical classification is concerned, we took a rather neutral position on the interpretation of findings and wrote in the discussion section: “Regardless of the classification of the tubarial glands as either a conglomerate of minor glands, a major gland, a separate organ, or as a new part of an organ system, the tubarial glands are macroscopic gland tissue locations with clinical relevance“. We thank Nascimento et al., Iwanaga et al., Mudry et al., Cohen Goldemberg et al., Narayan et al. and Schumann for their comments regarding the aspects mentioned above [4,8–12].
It is too early to call this gland a salivary gland
We thank Bikker and Vissink for their constructive input concerning the interpretation of the glandular structure that was described in the tubarial gland paper [3,13]. They argue that it is too early to call this gland a salivary gland for several reasons.
First, the question is raised whether the acinar cells actually produce saliva, as the authors of the letter seem to have set this as a criterium for the glands to be called salivary glands. The problem in answering that question, is that saliva is not strictly defined, as all fluids that contribute to the fluid in the oral cavity together are called saliva. These fluids are produced in the major (parotid, submandibular and sublingual) and minor (spread out microscopic) salivary glands and gingival crevice and have widely ranging compositions [14]. As an example, the amylase concentration varies by