Aneurysmal bone cyst of the orbit.

Aneurysmal bone cysts of the skull are rare, and orbital involvement of these cysts is even less frequent. We present CT, MR imaging, and histopathologic findings of an aneurysmal bone cyst of the orbit in a 13-year-old female adolescent. The tumor mainly involved the frontal bone. MR imaging findings of the aneurysmal bone cyst of the skull were highly suggestive of the diagnosis.