Aneurysmal bone cyst of the orbit: a case report and review of literature.

Aneurysmal bone cyst is a benign fibroosseous lesion which rarely occurs in the orbit. We report on a 7-year-old girl with aneurysmal bone cyst of the orbit who presented with painless proptosis and diplopia. Optic nerve compression resulted in field loss and delayed visual evoked potentials. Radiological and histological features are discussed. The lesion was excised via a frontal craniotomy and the orbital roof reconstructed with a prefabricated titanium plate. Post-operatively a rapid resolution of the proptosis and diplopia followed. Previous reported cases of this rare entity in the orbit are also reviewed.