Cementomas. II. Aggressive cemento-ossifying fibroma of the ethmoid region.

Aggressive cemento-ossifying fibroma is the most aggressive tumor of all cementum-containing neoplasms. An extensive, destructive cemento-ossifying fibroma of the ethmoid region was found in a patient. To our knowledge, this is the first case of a cemento-ossifying fibroma in this location. A radical maxillectomy was ultimately required to control the tumor, preserving orbital contents. The unique site of origin is thought to be the result of an ectopic periodontal membrane or of a primitive mesenchymal cell rest.