Facial schwannoma: results of a large case series and review.

OBJECTIVES AND HYPOTHESIS: To report a series of 53 cases of facial schwannoma, to review the current literature, addressing contentious issues, and to present a management algorithm. STUDY
DESIGN: Retrospective case review combined with review of current literature.
MATERIALS AND METHODS: A review of the case notes of 53 patients with intracranial and intratemporal facial schwannoma, from two tertiary referral centres, was undertaken. This represents the largest series of facial schwannomas with clinical correlations in the literature. Data relating to epidemiological, clinical and management details were tabulated and compared with other large series. A review of the current literature was performed, and a management algorithm presented.
RESULTS: There were 23 (43 per cent) female and 30 (57 per cent) male patients. Patients' ages at presentation ranged from five to 84 years, with a mean of 49 years. Twenty-five (47 per cent) of the tumours were present on the left side and 28 (53 per cent) on the right side. Hearing loss was the most common presenting symptom, being present in 31/53 (58 per cent) patients, followed by facial weakness in 27/53 (51 per cent). Two patients (4 per cent) were completely asymptomatic, and their facial neuromas were diagnosed incidentally. The schwannoma extended along more than one segment of the facial nerve in 39 patients (74 per cent), with the mean number of segments involved being 2.5. A conservative approach of clinical observation was undertaken in 20 patients (38 per cent). Thirty-three patients (62 per cent) underwent surgery, with a total of 36 procedures. The translabyrinthine approach was most common, being utilised in 17 of the 36 procedures. Two patients underwent revision surgery for residual or recurrent disease on three occasions. There was total removal of tumour in 21 cases; the remainder had subtotal or no removal with drainage or decompression of the tumours. Twenty-one nerve reconstructions were performed, and 18 facial rehabilitation procedures were performed on 14 patients. DISCUSSION: The results of this case series are similar to those of other reported series. The diagnosis of facial schwannoma is now generally made pre-operatively, due to improved imaging techniques and heightened awareness. Clinical assessment of facial function and imaging form the mainstays of surveillance for these tumours. These tumours are managed via clinical observation or surgical intervention; the latter can range from simple procedures (such as drainage of cystic components) to aggressive tumour removal and facial nerve reconstruction. Facial rehabilitation procedures may also be applied. The timing of intervention is contentious; surgical intervention is indicated when facial function deteriorates to a House-Brackmann grade IV level.
CONCLUSION: Facial schwannomas are rare lesions, and reported series are generally small. Due to the complex management issues involved, these tumours are best managed in a tertiary referral setting. Observation is preferred until facial function deteriorates to a House-Brackmann grade III level, at which time surgery is considered. When facial function deteriorates to House-Brackmann grade IV, surgical intervention is indicated. We advocate surgical management based on the treatment algorithm described.