Aneurysmal bone cyst of the maxilla.

An aneurysmal bone cyst of the maxilla is a nonneoplastic, uncommon, solitary bone lesion recognized by distinct radiographic and histopathological characteristics. It is described as a localized and quickly expandable benign tumor, which can reach a considerable size. It is characterized by the replacement of bone by spongy fibro-osseous tissue and a locally destructive and multicystic lesion filled with blood. It is attributed to a circulatory disturbance leading to locally increased venous pressure but with an unclear etiology. It takes place mainly in the long bones and in patients less than 20 years old, with no sex predilection. Its treatment is by surgical excision. An aneurysmal bone cyst in the facial bone is rare. The present case describes the lesion arising in the maxilla of a 14-year-old girl.