Organ of Chievitz.

The organ of Chievitz (also called the juxtaoral organ) is a small structure located within the soft tissue overlying the angle of the mandible in the buccotemporal space. The angle between the medial surface of the mandible and the buccinator muscle limits the buccotemporal space. The juxtaoral organ was first described in 1885 by the Danish anatomist Chievitz, who was studying the development of the salivary glands. Today, the organ of Chievitz is believed to represent an anlage of the parotid gland. However, it maintains no true connection with the parotid or oral cavity.

The small (~0.7 x 0.2 cm) fusiform juxtaoral structure is interposed between the fascia of the buccotemporal and pterygoid muscles, and it is innervated by a few twigs of the buccal nerve. Microscopically, it is made up of an epithelial parenchyma that is embedded in a highly organized connective tissue stroma rich in nerves and sensory receptors (figure). The epithelium forms multilobulated, circumscribed cell nests that rest on a basement membrane. The epithelial cells usually resemble those in nonkeratinizing squamous epithelium; less commonly, they resemble columnar gland-like cells with a clear cytoplasm, and in rare cases they resemble duct-like structures. The parenchyma is metabolically active, and it contains several enzymes that are similar to those found in the ductal cells of the salivary glands. The encasing connective tissue is organized into a three-layered capsule that contains nerve fibers, sensory receptors, and neurosecretory-like granules. The organ of Chievitz is thought to function as a mechanosensor in the lateral wall of the oral cavity that is involved in deglutition, sucking, mastication, and speech; therefore, unnecessary surgical removal is best avoided.

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In children, a normal juxtaoral organ may be discovered as a small mass in the cheeks. Without the knowledge that this is a normal structure, the otolaryngologist might embark on extensive and unnecessary investigations. Abnormalities arising from the juxtaoral organ are rare, and carcinoma has not been reported. The most significant concern is that the juxtaoral organ may be mistaken microscopically for perineural invasion by a carcinoma in biopsy specimens and in surgical resections that have been removed for nearby neoplasms. Therefore, awareness of this normal anatomic structure, in which epithelial islands are intimately admixed with nerves, is important to avert unnecessary surgery.

Suggested reading

Pantanowitz L. Balogh K. Significance of the juxtaoral organ (of Chievitz). Head Neck 2003;25:400-5.

Tschen JA, Fechner RE. The juxtaoral organ of Chievitz. Am J Surg Pathol 1979;3:147-50.

From the Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston.