Monday 26 October 2009
The nasopalatine duct cyst is located within the nasopalatine canal that runs from nose to the oral cavity through the midline of the anterior bony palate, just posterior to the central incisor teeth.
The cyst arises from epithelial remnants of the nasopalatine duct, and its lining may be pseudostratified columnar ciliated epithelium, stratified squamous epithelium, columnar or cuboidal epithelium and combinations of these.
As surgical treatment comprises emptying the nasopalatine canal, the specimen always includes the artery and nerve that run in this anatomical structure.
These are seen within the fibrous cyst wall and form the most convincing diagnostic feature for this cyst, as the specific appearance of the epithelial lining may be obscured by inflammatory changes.
Nasolabial cysts are located in the soft tissue just lateral to the nose at the lateral aspect of the maxillary alveolar process and are thought to arise from the nasolacrimal duct.
Non-ciliated pseudostratified columnar epithelium with interspersed mucous cells forms the epithelial lining. These features may be lost through squamous metaplasia. Apocrine metaplasia of the cyst lining has also been reported.