Aneurysmal bone cyst of the upper maxilla.

Aneurysmal bone cyst is a nosologic entity of low frequency that appears with greater incidence in large bones. Its presence in the upper maxilla is very rare, even more so in a thirteen year old boy. The author presents the case of an aneurysmal bone cyst of the upper maxilla, together with its investigations and the surgical treatment practiced in 1987. A comment is added on the surgical technique he might adapt nowadays for approaching this type of tumors.