Ossifying fibroma involving the paranasal sinuses, orbit, and anterior cranial fossa: case report.

We report a case of ossifying fibroma involving the paranasal sinuses, orbit, and anterior cranial fossa. Ossifying fibroma is a benign fibro-osseous tumor, rarely involving the anterior cranial base. The patient was admitted because of exophthalmos and diplopia. The lesion was totally removed surgically. Grossly, it had a thin osseous capsule. The microscopic examination showed mainly fibrous tissues and lamellar bone trabeculae rimmed by osteoblasts and myxomatous areas in some parts. The histopathological aspect of this entity is discussed with reference to the differential diagnosis from monostotic fibrous dysplasia.