Intratemporal facial nerve schwannomas: multicenter experience of 80 cases.

Purpose: To provide more data on the clinical presentation and natural evolution of facial nerve schwannomas and to provide guidance for therapeutic decision making.

Methods: A retrospective case review of eighty patients diagnosed with a facial nerve schwannoma between 1990 and 2018 in ten tertiary referral centers in Europe was performed. Patients' demographics, symptomatology, audiometry, anatomical site (segments involved), size and whenever possible volume measurement were registered.

Results: At presentation, transient or persistent facial palsy was the most common symptom, followed by hearing loss. The schwannoma involved more than one segment in the majority of the patients with the geniculate ganglion being most commonly involved. Initial treatment consisted of a wait and scan approach in 67.5%, surgery in 30% and radiation therapy in 2.5% of the patients. Tympanic segment schwannomas caused mainly conductive hearing loss and were more prone to develop facial palsy at follow-up. Internal auditory canal or cerebellopontine angle schwannomas presented with significantly more sensorineural hearing loss.

Conclusions: Although modern imaging has improved diagnosis of this tumor, choosing the best treatment modality remains a real challenge. Based on the literature review and current findings, more insights into the clinical course and the management of facial nerve schwannomas are provided.