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

Abstract

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.

The Juxtaoral Organ: From Anatomy to Clinical Relevance

“…In an extensive literature review, Kennedy [ 2 ] reported that the most commonly described anatomical location of the juxtaoral organ is lingual to the mandible, but in keeping with published cases, it can also be found buccal to the mandible and in the posterior tongue.…”

“…The procedure of differential diagnosis, ensuring there is no misinterpretation and thus correctly identifying this organ, lies in the understanding of its anatomical, morphological and cytological features; clinical features are rarely helpful [ 4 , 5 , 14 , 22 ]. Kennedy [ 2 ], when identifying the standard for the correct juxtaoral organ diagnostic procedure, emphasized the fact that morphological and anatomical criteria, in contrast to clinical features, may help to differentiate between the juxtaoral organ and infiltrating carcinoma, as summarized in Table 1 .…”

“…The juxtaoral organ parenchyma presents non-keratinizing squamous epithelial cells organized in multilobulated and interconnected nests of different sizes and shapes, which may form pseudolumens [ 4 , 21 , 27 ]. These epithelial cells do not display mitotic figures and cytoplasmic clearing; brown pigmentation and dystrophic calcification may be observed occasionally [ 2 , 4 ].…”

“…Some authors have demonstrated that the juxtaoral organ cell nests are immunohistochemically positive for vimentin, epithelial membrane antigen (weakly reactive), desmin, melan-A, a wide spectrum of cytokeratins and neuroendocrine markers (such as chromogranin, synaptophysin and neuron-specific enolase) [ 10 , 28 , 30 ]. The central epithelial cells are positive for cytokeratin 19 and the peripheral basal cells are positive for high molecular-weight keratin; however, no expression of S100 protein was observed [ 2 ]. The positivity for cytokeratins suggests that the juxtaoral organ epithelial nests share the immunohistochemical phenotype with non-keratinized stratified squamous cells [ 10 , 28 ].…”

“…The ‘Chievitz Organ’ is a neuroepithelial (primarily) bilateral anatomical structure located laterally to the walls of the oral cavity and featuring circumscribed epithelial cell nests [ 1 , 2 , 3 , 4 , 5 ].…”