Lateral periodontal cyst of the anterior maxilla: a rare case report

The lateral periodontal cyst (LPC) is a rare developmental odontogenic cyst, constituting approximately 0.4% of all odontogenic cysts and 0.7% of all jawbone cysts. It is an intraosseous, non-keratinized, non-inflammatory, developmental odontogenic cyst of epithelial origin, typically occurring adjacent to the root of a vital tooth. The lesion usually measures less than one centimeter in diameter. However, in the present case, the lesion was larger, measuring 3.5 × 2.4 × 2.4 cm. Radiographically, LPCs present as unilocular, round, oval or teardrop-shaped radiolucent lesions with a sclerotic border, located laterally to the tooth roots.

A 42-year-old female presented to the Oral and Maxillofacial Surgery outpatient department with a chief complaint of swelling on the anterior maxilla for one year. The swelling was asymptomatic, with no associated pain or discomfort. Clinical examination revealed a non-tender, fluctuant swelling on the left side of the anterior maxilla, located between the lateral incisor and canine teeth. A computed tomographic scan confirmed the presence of a lytic lesion on the left side of the anterior maxilla. Surgical enucleation of the cyst was performed through an intraoral crevicular approach under general anesthesia. The excised specimen was sent for histopathological examination. Histopathological examination of the cyst wall revealed a non-keratinized, non-ciliated stratified squamous epithelial lining, ranging from 1 to 5 cell layers in thickness. Interspersed among the epithelial cells were foci of Periodic Acid-Schiff (PAS) positive, glycogen-rich clear cells. Additionally, focal nodular areas of epithelial thickening with a whorled, swirling architecture were observed in continuity with the epithelial lining. The underlying subepithelial connective tissue was fibrous and exhibited a zone of hyalinization. These features were consistent with a diagnosis of lateral periodontal cyst. The healing process was uneventful, and no complications were observed during the one-year follow-up.

Although the lateral periodontal cyst is a rare developmental odontogenic cyst, it should be considered in the differential diagnosis of cystic lesions adjacent to the root of a vital tooth. Surgical enucleation remains the treatment of choice, with histopathological examination confirming the diagnosis. Recurrence of lateral periodontal cysts is infrequent.