An inverted papilloma isolated to the sphenoid sinus in a pediatric patient

A preoperative coronal (A and B) and axial (C) computed tomography scan demonstrates near-total opacification of both maxillary sinuses and the left sphenoid sinus.

Histological appearance demonstrating an inverted papilloma with an endophytic or inverted growth pattern. A thickened squamous epithelium grows downward into the myxoid stroma (hematoxylin and eosin; 100×).

Intraoperative imaging from the computer-aided image-guided navigation system shows the most superior and posterior site of the left sphenoid sinus.

A postoperative endoscopic view shows no recurrence of the inverted papilloma in the sphenoid sinus. Asterisk (*) indicates a part of the intersinus septum that has been resected: FL: floor; OC: optic canal.