Nasolabial cyst: case report with respect to immunohistochemical findings

The nasolabial cyst is a rare, usually unilateral lesion arising in the soft tissues adjacent to the alveolar process of the anterior maxilla, above the apices of frontal teeth and below the alar base. The typical clinical features of nasolabial cysts are: swelling between the upper lip and nasal aperture caused by a smooth and fluctuant, well defined space-occupying lesion, elevation of the nasal ala and obliteration of the nasolabial fold. This report describes some clinical, radiological and morphological findings in a nasolabial cyst. The cyst was lined up with bilayered epithelium showing scattered goblet cells. The immunohistochemical analysis revealed that the basaloid epithelial cells exhibited nuclear positive reactions for p63. The proliferative activity of the epithelial cells was low (<5%). Reaction for podoplanin was only discretely positive in basal cells within the non-inflamed portions but was enhanced in areas with inflammatory changes of the cyst wall. Cytokeratin subtyping showed a distinct expression of intermediate filaments in the nasolabial cyst. Nasolabial cysts are developmental cysts that can be cured by adequate surgical techniques. The expression pattern of podoplanin in this entity points to an association of this protein expression with inflammatory reactions to the cyst.