Median palatine cyst.

Median palatine cysts are rare, nonodontogenic lesion of the hard palate that do not involve the palatine papilla or incisive canal and that usually present as asymptomatic, fluctuant swellings. They may involve the floor the nasal cavity but are treated by simple enucleation, without recurrence. They are composed histologically of a fibrous collagenous tissue wall, with infiltration of chronic inflammatory cells, and lined by stratified squamous and/or respiratory epithelium. They are differentiated from the nasopalatine and other anterior maxillary cysts by the following diagnostic criteria: Appears grossly to be symmetrical along the midline of the hard palate. Located posterior to palatine papilla. Radiographically ovoid or circular in appearance. Not intimately associated with a nonvital tooth or found to have any communication with the incisive canal. Shows no histologic evidence of nerve trunks, large vascular spaces, hyaline cartilage, or accessory salivary gland tissue in the cyst wall.