Facial nerve schwannoma

Abstract

20th Rhinocamp Meeting Proceedings9-12 May, 2018 Marmaris • TURKEY18ORAL PRESENTATION 1-8Facial Nerve Schwannoma: Case ReportSedat Aydın1, Mehmet Gökhan Demir2, Derya Berk1, Sevtap Akbulut1, Kayhan Başak3, Tolga Çakıl11Kartal Dr.Lutfi Kirdar Education and Research Hospital, ENT Department,Istanbul 2Etimesgut State Hospital, ENT department, Ankara 3Kartal Dr.Lutfi Kirdar Education and Research Hospital, Pathology Department, IstanbulAbstract: Facial nerve schwannoma is a rare benign tumor of the temporal bone. It mıght cause hearing loss, facial nerve paresisor paralyses. We present a forty-six years old male patient who diagnosed facial nerve schwannoma on the timpanic segment.We have operated the patient via transmastoid approach successfully. On the follow up the patients facial paralyses is notrecovered so upper eyelid implant and canthopexy methods applied.Keywords: Schwannoma, facial nerve, surgical treatment.Introduction: Facial nerve schwannoma is a rare benign tumor which can be seen on facial nerve. It is difficult to separete fromvestibuler schwannoma with magnetic resonance imaging (MRI). General somatic sensorial branch, and taste branches of thefacial nerve is located on geniculate ganglion. Although facial nerve involvement by schwannoma is a rare entity, it might bepresented by newly onset facial nerve paresis or paralyses, conductive type hearing loss due to otitis media or mass effect (1).We are presenting a facial nerve schwannoma of the tympanic segment which obstruct mastoid segment and cause facial nerveparalyses, treated via transmastoid surgical excision successfully.Case Report: Forty six years old male patient is admitted to outpatient clinic with complaint of ongoing ear drainage 7 monthsago. Patient was prescribed with local antibiotherapy but otitis media was not healed so he was operated. During surgery itwas recognised that there was a mass on the middle ear cavity so surgeon took biopsy and decided to finalize the surgery.The pathologic investigation was facial nerve schwannoma so the patient was refered to our clinic. On physical examination thepatient has house brackman (HB) stage 3 facial paralyses. After MRI and CT scan investigation the patient is decided to operatewith transmastoid approach (Figure 1,2). During surgery we have recognised that facial nerve of tympanic segment is defective.The tumor arised from this segment and spreaded to mastoid segment. Malleus and incus bones were eroded duo to tumor andtegment tympany also eroded but dura was intact. All the tumor was resected successfullly. The pathologic investigation alsoshowed the schwannoma (Figure 3) After surgery facial nerve paralyses remained stabil so plastic surgery clinic applied uppereyelid implant and canthopexy.Discussion: Facial nerve tumors might be seen any part of the facial nerve but commonly seen on perigeniculate and tympanicsegment. In our case the tumor was detected on the tympanic segment. Most typical symptoms are facial nerve paresis orparalyses, hearing loss, tinnitus, otorhea, otalgia and vestibular symptoms (2).In our case both facial paralysis and otorheawere detected. Facial nerve schwannoma is the most common tumor of the facial nerve. Saito et al. showed in a study thatintratemporal schwannoma has a incidence of 0.8 % in a 600 temporal bone material (3). In our case we have diagnosed thetumor on the tympanic segment. Facial nerve schwannoma can be treated by microsurgery methods. Facial nerve functionsshould be supplied by these methods. Treatment methods are wait and observe, fallopian canal decompression and steotaxicsurgery (4). In our case we decided to perform surgery due to facial nerve paralysis and otorhea. If there is not any facialweakness, the method which preserve the facial function, should be used in first response. On the other hand , when the facialnerve paralysis, labyrinthine segment erosion or brainstem compression are detected the facial nerve might not be preservedduring surgery (5). In our case we performed the transmastoid approach to excise the facial nerve schwannoma. At the end of thesurgery the facial nerve function is not changed. In order to supply the eye clousure, plastic surgeon performed the canthopexyand upper eyelid implant. On the follow up we do not detect any recurrence. We should keep in mind the facial nerve schwannmain middle ear cholesteatoma cases.References1. Kirazlı T, Oner K, Bilgen C, Ovul I, Midilli R. Facial nerve neuroma: Clinical,Diagnostic and surgical features. Skull base. 2014;14:115-120.2. O’Donoghue GM, Brackmann DE, House JW, Jackler RK. Neuromas of the facial nerve. Am J Otol. 1989;10:49–543. Saito H, Baxter A. Undiagnosed intratemporal facial nerve neurilemomas. Arch Otolaryngol. 1972;95:415–419.4. Minovi A, Vosschulte R, Hofmann E, Draf W, Bockmuhl U. Facial nerve neuroma: surgical concept and functional results. SkullBase. 14:195–200. discussion 200–191, 2004.5. Shirazi