title: Large facial nerve schwannomas without facial palsy: case reports and review of the literature.
abstract: Although approximately 30% of facial nerve schwannoma cases present with no facial palsy, a large facial nerve schwannoma extending to the middle and posterior cranial fossa quite rarely presents without facial palsy. The authors encountered two patients with large facial nerve schwannoma who presented with only hearing impairment and no facial palsy. The first patient was a 64-year-old woman who presented with right auditory impairment without facial palsy. MR images demonstrated a dumbbell-shaped tumor in the cerebellopontine angle. Another patient, a 40-year-old woman, also presented with vertigo and right tinnitus without facial palsy. MR images demonstrated a huge tumor expanding into both the posterior cranial fossa and middle cranial fossa. In both cases, intraoperative findings confirmed that the tumors had grown from the facial nerve. Facial nerve schwannoma can be easily diagnosed if detailed neurological evaluations and appropriate neuroimagings are conducted. However, in spite of such huge tumoral size and expanding pattern, the facial nerve function was relatively preserved. Anatomical features of the facial schwannoma are discussed. A tumor extending to the middle and posterior cranial fossa should remind neurosurgeons to consider facial nerve schwannomas even in the absence of facial palsy.
authors.affiliation: Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, 8-1 Kawada-Cho, Tokyo, 162-8666, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kubota
authors.forename: Takakazu
authors.initials: T
authors.lastname: Kawamata
authors.forename: Osami
authors.initials: O
authors.lastname: Kubo
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kasuya
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Muragaki
authors.forename: Tomokatsu
authors.initials: T
authors.lastname: Hori
mesh_terms: D000368:Aged; D001037:Aphasia / Q000209:etiology; D005260:Female; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D010291:Paresis / Q000209:etiology