Juxtaoral organ of Chievitz, radiologically suspicious for invasion of lingual squamous cell carcinoma

The Juxtaoral Organ: From Anatomy to Clinical Relevance

The juxtaoral organ was first described 1885 as a rudimentary structure that developed and disappeared in the embryonic period. Since then, it has been studied further and is now known to be a permanent anatomical structure of considerable importance in clinical, surgical and pathological fields. However, there are no precise and uniform descriptions about its anatomical localization and functional significance. Precise and in-depth anatomical knowledge is crucial to reducing the risk of incorrect identification of the juxtaoral organ, due to fact that this anatomical structure can be misinterpreted as a carcinoma, leading to unnecessary treatments. Therefore, the purpose of this review is to summarize the actual knowledge on the gross and microscopic anatomy of the juxtaoral organ and outline its clinical relevance in order to prevent unnecessary investigations/treatments of this anatomical pitfall. We believe that further studies are still needed to add new perspectives in relation to the juxtaoral organ.

The juxta-oral organ of Chievitz (organum yuxtaorale) updated: Embryology, anatomy, function and pathology

BACKGROUND

The Chievitz's organ or juxta-oral organ is a mysterious bilateral structure, phylogenetically preserved, which develops from the mouth epithelium as an invagination that loses connection to it in the prenatal period. It is located laterally to the walls of the oral cavity in an imprecise anatomical location and receives abundant innervation from the buccal nerve. Structurally it consists of non-keratinizing squamous-like neuroepithelial cells surrounded by two layers of connective tissue with nerve fibers and different morphotypes of sensory corpuscles. Its function is completely unknown although based on its rich innervation it is assumed that works as a mechanoreceptor.

METHODS

We have performed immunohistochemistry for axonal and Schwann cells, and the putative mechanoproteins ASIC2, TRPV4 and Piezo2 in sections of fetal juxta-oral organ.

RESULTS

Intraparenchymatous nerve fibers and sensory corpuscles were observed as well as immunoreactivity for Piezo2 in both nerve fibers and epithelial parenchymatous cells.

CONCLUSIONS

We add indirect evidence that the juxtaoral organ is a mechanoreceptor because in addition to its dense innervation, the epithelial cells and sensory nerve fibers display immunoreactivity for the mechanogated ion channel Piezo2. Based on current knowledge, the functional and clinical importance of the juxta-oral organ should be further investigated.

Neuroepithelial Structures of the Oral Soft Tissues Including the Juxtaoral Organ of Chievitz: A Literature Review and Audit of Diagnosed Cases

The juxtaoral organ of Chievitz (JOOC) is a part of microanatomy composed of bland epithelial islands closely associated with small nerves and usually described within the soft tissue on the lingual aspect of the posterior mandible. Similar structures are documented in the posterior tongue. There is a risk of misinterpretation as carcinoma showing perineural invasion. An audit was undertaken of diagnosed cases of the JOOC and similar neuroepithelial structures identified within the oral soft tissues of surgical specimens. Nineteen cases were identified. Epithelial islands ranged < 0.5-4 mm in maximum dimension and lay in close association with small nerves. Epithelial cells showed a squamoid appearance but were without keratinisation. There was no atypia and mitotic figures were not seen. In 53% of cases the epithelial cells showed cytoplasmic clearing, in 26% of cases there was brown pigment and in 11% of cases there were calcifications. In 53% of cases, these neuroepithelial structures lay within the soft tissue lingual to the mandible in the retromolar area, 26% of the structures were placed buccal to the mandible, 11% of the structures lay adjacent to the maxillary tuberosity and 11% of the structures were within the posterior tongue.

Juxtaoral organ of Chievitz: An innocuous organ to be known

The Juxtaoral Organ of Chievitz is a normal anatomical structure located within the soft tissue in the buccotemporal fascia on the medial surface of the ascending ramus. This enigmatic vestigial structure is considered to be of neuroepithelial origin with no known function. As a matter of fact, JOOC is one of the most treacherous pitfalls in surgical pathology with respect to lesions in the head and neck area. Hence the basic aim of this short communication is to reveal the importance about this organ and enlighten the oral pathologist about this histopathological structure, thus preventing extensive and unnecessary investigations.