Journal of Research in Medical Sciences1735-199516620110616Ossifying fibroma of the ethmoid sinus: Report of a rare case and review of literature66516651ENZhalehMohsenifarSaeed AllahNoohiFatemehMashhadi AbbasSarehFarhadiAssistant Professor, Department of Oral and Maxillofacial Pathology, School of Dentistry, Shahed University, Tehran, Iran.. dr.sfarhadi@gmail.comBehzadAbedin2011011820110531Ossifying fibroma (OF) is a benign fibro-osseous lesion which was first described by Menzel in 1872. It is commonly seen in the head and neck regions and represents an aggressive pattern when the midface and paranasal sinuses are involved. We report a 36 years old white woman with ossifying fibroma in the right ethmoid sinus. Computed Tomography (CT) scan images showed a hyperdense mass. Transnasal endoscopic resection was performed and histopathological examination confirmed the diagnosis of ossifying fibroma. The present case is notable because involvement of the ethmoid sinus is rare in this condition with only 48 cases reported in the literature until June 2011.KEYWORDS: Ossifying Fibroma, Ethmoid Sinus