Expansive Central Ossifying Fibroma of the Right Mandible.

This case report discusses a 28-year-old patient who presented with a large expansile lesion of the right mandible. A maxillofacial CT showed a 6.7 x 9.1 x 7.6 cm right mandibular cystic mass containing an internal matrix of ground glass bone, representing a huge odontogenic keratocyte. Upon biopsy of the lesion, the specimen consisted of non-decalcified irregular fragments of cemento-osseous material, embedded in a minimally hemorrhagic, cellular fibrous tissue stroma, suggestive of central ossifying fibroma. This case presents an ossifying fibroma that far exceeds the average size of these masses, which typically range from 1.0 to 2.5 cm at its greatest dimension. The immense size of the lesion seen in this case is rarely encountered. This case also helps to emphasize the importance of timely diagnosis and complete resection of the lesion to prevent mass recurrence and possible malignant transformation.