Sphenoid Sinus Mucocele with Clival and Sellar Extension Mimicking a Neoplastic Lesion: A Case Report

Paranasal sinus mucoceles are benign, encapsulated, cystic lesions lined by respiratory epithelium. These lesions arise from the obstruction of a sinus drainage ostium. Mucoceles represent one-tenth of sinus surgical pathology in adults. Sphenoid sinus mucocele constitutes less than 3% of all mucocele cases. A 28-year-old man with a history of chronic rhinosinusitis presented with a lesion causing expansion and erosion of the sphenoid sinus and clivus, which initially raised suspicion of a chordoma. The intraoperative study was consistent with a mucocele. The lesion was resected, and the patient's evolution was satisfactory. Sphenoid mucoceles are potentially dangerous lesions due to their ability to compress critical adjacent structures. Extension into the clivus, as observed in this case, is a rare presentation that can mimic neoplastic lesions such as chordomas.