Chronic Sphenoiditis With Deep Neck Space Extension: Case Report With Review of the Literature and Postulated Mechanisms for Extracranial Extension.

Isolated primary sphenoid sinusitis is a rare occurrence, estimated to make up less than 3% of sinus infections. The posterior anatomic location of the sphenoid makes treatment challenging when it becomes infected. Complications involving intracranial extension to surrounding structures often result in cranial nerve deficits due to their proximity. A single case of chronic sphenoiditis with direct extracranial extension into the prevertebral space is reported with a discussion on clinical presentation, diagnosis, and management. A 46-year-old female patient with diffuse headaches radiating into the neck and throat was evaluated in the office. Computed tomography demonstrated sphenoiditis with direct extension into the prevertebral space. Imaging revealed a purported route of direct extension through the clinoid and directly into the clivus to form an abscess in the longus colli muscle. The patient underwent endoscopic surgical management including drainage of the prevertebral abscess and has since made a full recovery. This is the first reported case of direct extension of sphenoiditis into the prevertebral space. The findings highlight the importance of aggressive treatment of chronic sphenoid infections to prevent detrimental complications. Computed tomography imaging proved an advantageous imaging modality to demonstrate bony erosion and sinus tracts from the skull base to the deep neck space.