Fibro-osseous lesions of the face and skull with aneurysmal bone cyst formation.

Aneurysmal bone cyst engraftment on benign fibro-osseous lesions, well known to occur in the extracranial skeleton, has been reported infrequently in the craniofacial bones. When this combined lesion occurs in the skull the clinical and radiographic features often suggest an aggressive neoplasm. The clinical, radiographic, and pathologic features of five cases are presented, and this uncommon lesion of the craniofacial bones is discussed in view of these cases and those reported in the literature.