Eustachian tube lumen opening into an abnormally pneumatized sphenoid bone.

Morphological abnormalities of left temporal and sphenoid bone were discovered in a 17-year-old boy during a post-traumatic cranial CT scan examination. The patient had not suffered from audiological disorders previously. He did not complain of hearing loss, vertigo or autophony. Further clinical investigations were normal including micro-otoscopy and nasopharyngeal endoscopy. The Valsalva maneuver was correctly performed. Audiometry and tympanometry were without any particularity. These abnormalities consist of a subdivision of the pharyngeal part of the lumen of the Eustachian tube and an abnormal pneumatization of the sphenoid bone. The lower part of the tubal subdivision, proximally slightly larger than normal, opens as usual onto the nasopharynx. The upper part reaches a “mastoid-like” pneumatization of the sphenoid body (Fig. A, B & C: axial, coronal oblique and Minimum Intensity Projection views – arrow and asterisk). The left pterygoid process is also unusually pneumatized and the left temporal bone is more pneumatized than the right. Note that sphenoid sinuses are hypoplastic.