Facial nerve schwannomas: a report of four cases and a review of the literature

Abstract

Objective: To evaluate both the surgical approaches and results of the facial nerve schwannoma cases as diagnosed in our clinic in line with the literature.

Material and methods: The files of 4 cases diagnosed in our clinic as facial nerve schwannoma between 1996 to 2002 were reviewed retrospectively. All the cases were evaluated with detailed history; ear, nose, and throat examination; computed tomography; and/or magnetic resonance imaging. If required, electromyography and audiometric evaluations were made. Fine-needle aspiration cytology was also performed in appropriate cases. The surgical approach used was determined depending on the tumor location and its extent. Facial nerve reconstruction was accomplished if the integrity of the nerve could not be protected. Cases were followed up for facial nerve function, complications, and recurrence.

Results: The tumors occurred in the vertical (n = 2), internal auditory canal (n = 1), and the peripheric segment (n = 1) of the nerve. As symptoms, facial paralysis (n = 2), hearing loss (n = 3), tinnitus (n = 1), otorrhea (n = 2), parotid mass (n = 2), and external auditory canal mass (n = 1) were observed. Radiologic investigations provided important informations. However, fine-needle aspiration cytology did not contribute to a correct preoperative diagnosis. The superficial parotidectomy approach (n = 1), retrosigmoid approach (n = 1), and transmastoid-superficial parotidectomy combined approach (n = 2) were used. The integrity of the nerve could not be protected in 3 of the cases. After the reconstruction surgery, the facial nerve function was evaluated as House-Brackmann grade 3 for all 3 cases at the mean 38.6 months follow-up time. No tumors have recurred during follow-up.

Conclusion: Facial nerve schwannoma is a rare tumor. Through improved surgical and reconstruction techniques, postoperative morbidity is at acceptable levels. The rate of recurrence is low. It should be kept in mind for differential diagnosis of facial nerve paralysis.