Conservative management of an atypical intra-sinusal ossifying fibroma associated to an aneurysmal bone cyst.

Ossifying fibroma (OF) is a benign fibro-osseous lesion mainly occurring in young adults and seems to originate from the periodontal ligament. Aneurysmal bone cyst (ABC) is a benign intraosseous lesion characterized by blood-filled spaces of various sizes. These two lesions can specifically affect the jaws and are commonly described in the literature. However, few cases describing an association of OF and ABC have been reported in the literature, especially in the maxillary sinus. We report the case of a 40-year-old male patient affected with an asymptomatic lesion with a dual component of OF and ABC laying in the maxillary sinus. Our aim is to discuss its clinical and morphological features as well as treatment results.