A case of peripheral keratocystic odontogenic tumor arising in the incisal gingiva of the mandible

Abstract

Keratocystic odontogenic tumor commonly occurs in the posterior body and ramus of the mandible. Rarely, however, it develops in the attached gingiva or alveolar mucosa and exhibits the same histopathologic features. The lesion clinically resembles a gingival cyst in adults. Differential diagnosis is therefore difficult. We encountered a case of keratocystic odontogenic tumor arising in the mandibular gingiva and report it as a peripheral keratocystic odontogenic tumor.A 53-year-old man was referred to our department because of an asymptomatic swelling measuring 6 mm in diameter at the gingiva attached to the labia near teeth 2 3. The swelling was covered with normally appearing mucosa and had a whitish hue. The lesion was fluctuant on palpation and had neither spontaneous pain nor tenderness. The teeth adjacent to the lesion were noncarious, and confirmed pulp vitality by electrical stimulation. The lesion was totally excised with a 1-mm margin of normal gingiva under local anesthesia. The alveolar bone adjacent to the lesion had undergone pressure resorption. Exposure of the root surface of 2 3 was noted intraoperatively. Histopathologically, a cystic space was located within the gingival soft tissue. It was lined by parakeratotic stratified squamous epithelium composed of several cell layers and lacking rete pegs. No recurrence was noted for 6 years.