Infrasellar craniopharyngioma.

A rare case of infrasellar craniopharyngioma mainly occupying the paranasal sinuses, the infratemporal fossa and the skull base is presented. The patient had been treated by an otolaryngologist as a case of mucocele of the sphenoid and ethmoid sinuses because the biopsy specimens obtained at endonasal surgery failed to confirm the true diagnosis. Computed tomography (CT) showed multi-lobulated low density cysts in the paranasal sinuses, infratemporal fossa and skull base, and the cyst wall was enhanced. Magnetic resonance Imaging (MRI) revealed the cysts to have high intensity in both T1- and T2-weighted images, and excellent three-dimensional visualization was obtained. Characteristic motor-oil-like fluid was aspirated during transnasal surgery and the diagnosis of craniopharyngioma was confirmed by histological examination.