Lateral periodontal cyst in an interdental molar site: Novel presentation in a geriatric patient.

Objective: This report describes an unusual case of a lateral periodontal cyst (LPC) residing between the roots of a mandibular first and second molar.

Background: The LPC is a developmental odontogenic cyst, the majority situated along the lateral roots of the mandibular canines and premolars. The occurrence of an LPC solely confined to the molar region is extremely rare. Limited information regarding the LPC has appeared in the geriatric literature.

Patient Presentation: A unilocular cyst-like lesion was incidentally discovered on extraoral and intraoral radiographic examinations involving a 68-year-old patient. It was initially considered an infected odontogenic keratocyst or unicystic ameloblastoma.

Results: Histologic examination of the excised specimen revealed a thin cuboidal epithelial lining with focal nodular thickenings and underlying fibrovascular connective tissue wall. The lesion was diagnosed as an LPC. At a 6-month follow-up, the patient has remained asymptomatic and exhibited radiographic osseous regeneration.

Conclusions: The LPC should be added to the differential diagnosis of developmental odontogenic cysts found in the inter-molar region. A preoperative cone beam computed tomography scan may be helpful to optimise the surgical approach. Timely removal of any suspected cystic lesion, particularly in the context of infection in an older patient, may reduce postoperative sequelae and rule out malignancy.