We thought that mucocele was most likely based on the imaging findings, and endoscopic sinus surgery was planned to remove it. When right sphenoidotomy was performed, a mass was found in the sphenoid sinus. A polypoidal capsule surrounded the mass, and fluid and fibrous tissue were present inside the mass (Fig. 2A). No evidence of the involvement of the superior and posterior wall of the sphenoid sinus, sella turcica, and dura mater was found. The pathologic findings indicated that the epithelial cells resemble ameloblastoma with peripheral palisading cells and central wet keratins (Fig. 2B). This finding is consistent with the pathologic findings on craniopharyngioma. No remarkable complications after surgery and recurrence after more than 5 years of follow-up were observed.