Giant aneurysmal bone cyst of the mandible.

The aneurysmal bone cyst is a type of pseudocysts of the jaw. It is a nonneoplastic lesion of the bone, characterized by replacement with fibro-osseous tissue containing blood-filled sinusoidal or cavernous spaces. The lesion remains a relatively uncommon finding in the facial bones, and the cause and pathogenesis are yet to be elucidated. Aneurysmal bone cyst was first described as a distinct clinical and pathologic entity by Jaffe and Lichtenstein in 1942. Aneurysmal bone cyst comprises 1.5% of all nonodontogenic cysts of the jaws and 1.9% of all aneurysmal bone cysts of skeleton. A rare case of giant aneurysmal bone cyst of mandible in a 10-year-old child is presented, which was managed by surgical curettage with a long-term follow-up.