A 55-year-old woman with an asymptomatic, nodular swelling located on the attached gingiva between the mandibular right first and second premolars was referred to the Department of Periodontology in Gülhane Military

recognized type of developmental odontogenic cyst. This lesion is more common in adults (1,2). Cohen et al. (2) reported an equal sex distribution, but other studies have reported a male preponderance (3,4). Differential diagnosis between lateral periodontal cyst and collateral keratocyst must be done by evaluating the clinical and histological data. It is also difficult to distinguish lateral periodontal cyst from gingival cyst in adults since they have many similarities. Radiolucent odontogenic tumors and benign mesenchymal tumors should also to be considered for differential diagnosis (2).