title: Facial Nerve Schwannomas: Review of 80 Cases Over 25 Years at Mayo Clinic.
abstract: OBJECTIVE
  To elucidate the long-term clinical behavior, treatment, and outcomes of sporadic facial nerve schwannoma (FNS) in a large cohort of patients managed in the post-magnetic resonance imaging era.
  
  
  METHODS
  Retrospective review at a single tertiary health care system (January 1, 1990, through December 31, 2015), evaluating 80 consecutive patients with sporadic FNS.
  
  
  RESULTS
  Ninety-eight patients with FNS were identified; 10 with incomplete data and 8 with neurofibromatosis type 2 were excluded. The remaining 80 patients (median age, 47 years; 58% women) were analyzed. Forty-three (54%) patients presented with asymmetrical hearing loss, 33 (41%) reported facial paresis, and 21 (26%) reported facial spasm. Seventeen (21%) exhibited radiologic features mimicking vestibular schwannoma, 14 (18%) presented as a parotid mass, and 5 (6%) were discovered incidentally. Factors predictive of facial nerve paresis or spasm before treatment were female sex and tumor involvement of the labyrinthine/geniculate and tympanic facial nerve segments. The median growth rate among growing FNS was 2.0 mm/y. Details regarding clinical outcome according to treatment modality are described.
  
  
  CONCLUSIONS
  In patients with FNS, female sex and involvement of the labyrinthine/geniculate and tympanic segments of the facial nerve predict a higher probability of facial paresis or spasm. When isolated to the posterior fossa or parotid gland, establishing a preoperative diagnosis of FNS is challenging. Treatment should be tailored according to tumor location and size, existing facial nerve function, patient priorities, and age. A management algorithm is presented, prioritizing long-term facial nerve function.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN; Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, MN. Electronic address: carlson.matthew@mayo.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Carlson
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Scottsdale, AZ.
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Deep
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Patel
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Jacksonville, FL.
authors.forename: Larry B
authors.initials: LB
authors.lastname: Lundy
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Tombers
authors.affiliation: Department of Health Sciences Research, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN; Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, MN; Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Driscoll
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003390:Cranial Nerve Neoplasms / Q000175:diagnosis* / Q000628:therapy; D003937:Diagnosis, Differential; D004244:Dizziness / Q000209:etiology; D005155:Facial Nerve Diseases / Q000175:diagnosis* / Q000628:therapy; D005158:Facial Paralysis / Q000209:etiology; D005260:Female; D006261:Headache / Q000209:etiology; D034381:Hearing Loss / Q000209:etiology; D019569:Hemifacial Spasm / Q000209:etiology; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009442:Neurilemmoma / Q000175:diagnosis* / Q000628:therapy; D063868:Patient Outcome Assessment; D012189:Retrospective Studies; D014012:Tinnitus / Q000209:etiology; D055815:Young Adult