A young, previously healthy girl presented with a 10-day history of progressive, left-sided facial palsy accompanied by ipsilateral hearing loss and decreased facial sensation. She had not experienced headaches, disequilibrium, or tinnitus. She had no history of trauma, and there was no response to steroids. Findings from a physical examination were notable for left House-Brackmann grade III/VI facial palsy, hypoesthesia in left trigeminal nerve distribution, and no left audiologic responses to bone or air stimuli. A non–contrast-enhanced computed tomographic (CT) scan showed a left petrous apex expansile lesion involving the internal auditory canal (Figure, A). Magnetic resonance imaging (MRI) showed a well-circumscribed lesion (Figure, B) extending into the fundus of the internal auditory canal (Figure, C). There was a fluid-fluid level in the lesion (Figure, B), consistent with presence of blood products. The displaced adjacent cranial nerve V (Figure, C) extended along the surface of the lesion. After the administration of an intravenous contrast agent, there was a nodular focus of enhancement at the anterior aspect of the lesion (Figure, D) and linear areas of enhancement at the periphery and of internal septations (Figure, D). The lesion was completely excised via a middle fossa craniotomy. Postoperatively, the patient regained full function of all cranial nerve deficits, including the hearing loss.
Espinel AG, Taheri MR, Monfared A. An Expansile Petrous Apex Mass. JAMA Otolaryngol Head Neck Surg. 2016;142(6):605-606. doi:10.1001/jamaoto.2016.0952