title: Circular enlargement of the optic canal caused by paranasal sinus mucocele.
mesh_terms: D000328:Adult; D006261:Headache / Q000209:etiology; D006801:Humans; D008297:Male; D009078:Mucocele / Q000150:complications / Q000000981:diagnostic imaging*; D009408:Nerve Compression Syndromes / Q000209:etiology; D009900:Optic Nerve; D010254:Paranasal Sinus Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D011859:Radiography; D013100:Sphenoid Bone / Q000000981:diagnostic imaging*; D014786:Vision Disorders / Q000209:etiology