RESUMO
Fibro-osseous lesions are common in the paranasal sinuses. The incidence of fibrous dysplasia (FD) in the ethmoid sinus is rare. Patients with such lesions are usually asymptomatic until the lesion is large enough to start compressing adjacent structures and organs. Common presentations include nasal obstruction, headache, eye swelling, and diplopia. Meanwhile, less common signs can include decreased visual acuity. We present a case of a 65-year-old male with comorbidities who presented to the clinic complaining of a chronic nasal obstruction, headache, and decreased visual acuity in the right eye. On endoscopic examination, a lesion was identified in the ethmoid sinus. Computed tomography was performed and confirmed the positioning of the lesion within the ethmoid sinus compressing the optic nerve. Total excision was performed through a direct nasal endoscopic approach. The lesion was excised completely with no recurrence. Histopathology report confirmed the lesion to be of cartilaginous nature, and a final diagnosis of cartilaginous fibrous osteoma was made. Such lesions are usually benign and symptomless. Excising the lesion completely is the best approach to decrease the chances of recurrence.