Unusual Sites for Extracranial Head–Neck Schwannomas

Abstract

Schwannomas are a frequent cause of swellings in the head and neck region. Due to the abundance of peripheral, cranial and autonomic nerves in this region, schwannomas can present in variety of locations, posing a diagnostic and therapeutic challenge to the surgeon. Unusual sites in head and neck region can have varied presentation depending on the site of origin. We identified unusual extracranial locations of head and neck schwannomas, their presenting features and surgical management. Retrospective review of cases of extracranial head and neck schwannomas operated in the Department of Otolaryngology and Head-Neck Surgery, All India Institute of Medical Sciences, New Delhi, a tertiary referral centre between July 2015 and June 2019. A total of 42 cases of extracranial head and neck schwannomas were operated. Among them, 9 cases were found to arise from uncommon sites, such as parotid gland (n = 1), infratemporal fossa (n = 2), external auditory canal (n = 1), subglottis (n = 1), false vocal cord (n = 1), frontal recess (n = 1), maxillary sinus (n = 1) and retromolar trigone (n = 1). All patients underwent excision via relevant approaches. Nerve of origin was identified in 4/9 cases. One case had postoperative neurological deficit. No recurrences were noted in mean follow-up of 19 months. Schwannomas ought to be considered as a differential diagnosis for swellings/ mass in any part of head and neck region. Comprehensive evaluation with appropriate imaging and histology should be done in all cases. Preoperative counselling and consent regarding neurological deficit pertaining to possible nerve of origin is required in each case.