Lateral Periodontal Cyst – A diagnostic dilemma: Report of a rare case with CBCT and histological findings

INTRODUCTION: Lateral Periodontal Cyst (LPC) is considered as a rare developmental odontogenic cyst. It is often diagnosed as an incidental radiographic finding, presenting as a circumscribed round radiolucent area between the roots of vital teeth. LPC usually does not present any clinical features. Differentiating the origin of the lesion from an endodontic or periodontal perspective presents as clinical challenge. PRESENTATION OF CASE: A female patient presented with an asymptomatic gingival swelling in the lingual aspect of mandibular anterior region. The associated tooth (#34) was endodontically treated 3 years back. A periapical radiograph showed a well-defined round radiolucency on the tooth. Cone beam computed tomography (CBCT) revealed extensive bone destruction. The lesion was surgically excised and histological examination confirmed the diagnosis of LPC. The site healed satisfactorily post-operatively. The case was followed up for a year without any recurrence seen. DISCUSSION: LPC is a very rare clinical entity, the diagnosis of which requires a detailed case history taking, clinical and radiographic examination are essential to get proper assessment of the pathology. It is said to originate from either the remnants of dental lamina, reduced enamel epithelium or rests of Malassez. LPC presents with a typical histological picture which ensures the confirmatory diagnosis. Surgical enucleation with thorough curettage is the treatment of choice. CONCLUSION: By reporting this rare case, we would like to stress to clinicians that there are a wide range of cysts and anatomic structures are present in the canine-premolar region of mandible of which LPC is a rare possibility.