[Aneurysmal bone cyst of the mandible: a case report].

Aneurysmal bone cyst is a benign lesion that is more commonly seen in long bones and the vertebra. Its occurrence in the craniofacial region is rare. A nine-year-old boy presented with a well-demarcated, painless, fixed mass, 3 x 3 cm in size, in the left preauricular region, with no fluctuation or crepitation. Computed tomography showed a lesion in the left mandibular ramus with a fluid-fluid level, extending to the mandibular condyle, with erosion to the adjacent cortex. Total curettage was performed via a transoral approach under general anesthesia. Histopathologic diagnosis was made as an aneurysmal bone cyst. No recurrence or complication were seen during a follow-up period of four years.