Cemento-ossifying fibroma: an extensive fibro-osseous lesion involving paranasal sinuses

Cemento-ossifying fibroma (COF) is a fibro-osseous lesion arising from cells of the periodontal ligament. This tumor typically occurs in individuals during their third and fourth decades of life, with a predilection for women. COF primarily affects the maxillofacial region, most commonly the mandible. Its localization in the paranasal sinuses and skull base is unusual. However, we present a rare case of COF involving the right paranasal areas of the maxillofacial region in an 18-year-old female. Computed tomography (CT) revealed an expansile lesion measuring 52.45×32×74.29 mm involving the right maxillary sinus, expanding into both the anterior and posterior choanae. The patient underwent endoscopic sinus surgery (ESS) with preservation of adjoining vascular structures. Clinical, radiographic, and histologic features are presented, and differential diagnosis is discussed.