Juxtaoral Organ of Chievitz |
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Organoid islands of squamoid/cuboidal epithelium. |
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Clinical Features
The juxtaoral organ was first described by Chievitz in 1885
and is considered to be a vestigial organ, perhaps of the developing parotid
gland, or to be epithelium entrapped during the embryonic development of
the interface between the maxillary and mandibular
processes. A neuroendocrine receptor function has been
suggested. It is present in almost all individuals and is located bilaterally
in buccotemporal fascia on the medial surface of the mandible, near the angle.
Until recently it was thought that the organ produces no visible or palpable
mass, it was an occasional incidental finding in biopsied tissue samples
from the region. A proliferative mass of the lingual aspect of the posterior
mandible has, however, now been reported as the first example of a tumor
of the juxtaoral organ. A similar structure has been found
within the anterior maxillary bone, but no embryonic explanation has been
offered for its presence in that location.
Pathology and Differential Diagnosis
The juxtaoral organ is a multilobulated nest or aggregation of 2-10 discrete islands of moderately large, oval or angular cells with a distinct squamoid appearance but with no keratin formation and with few, if any, intercellular bridges (Figures 1 & 2). Most islands also have smaller, darkly staining basaloid cells, usually aligned at the periphery, and a few show central epithelioid cells with clear cytoplasm. There is a definite glandular or organoid pattern. The background stroma is moderately dense fibrous tissue with no inflammatory infiltrate, no obvious encapsulation and perhaps with extracellular melanin deposits.
Characteristically, there is a prominent PAS-positive basement membrane around the epithelial islands and there are numerous small, myelinated, often degenerated nerves admixed with the epithelial islands. Occasional epithelial islands will demonstrate focal areas of dystrophic calcification.
A word of caution. Because the organ of Chievitz is located so deeply in
the soft tissues, it may be mistakenly interpreted by the pathologist as
well-differentiated squamous cell carcinoma, mucoepidermoid
carcinoma, or metastatic deposits from a visceral organ.
Treatment and Prognosis
While the function of this structure
is completely unknown, it is a very innocuous variation of normal anatomy
and requires no treatment. The single reported case of tumorous
growth of the organ had no recurrence 8 months after conservative surgical
removal.
References (Chronologic Order)
Note: General references can be found by clicking on that topic to the left.
Chievitz JH. Beitrage zur Entwicklungsgeschichte der Speicheldrusen. Arch Anat Physiol 1885; 9:401-436.
Eversole LR, Leider AS. Maxillary intraosseous neuroepithelial structures resembling those seen in the organ of Chievitz. Oral Surg Oral Med Oral Pathol 1978; 46:555-558.
Danforth RA, Baughman RA. Chievitz's organ: a potential pitfall in oral cancer diagnosis. Oral Surg Oral Med Oral Pathol 1979; 48:231-236.
Miko T, Molnar P. The juxtaoral organ: a pitfall for pathologists. J Pathol 1981; 133:17-23.
Vadmal MS, Rossi MB, Teichberg S, Hajdu SI. Intraoral tumor of Chievitz in a child. J Ped Pathol 1999, in press.
