Facial nerve schwannomas presenting as occluding external auditory canal masses: a therapeutic dilemma

Otol Neurotol. 2014 Aug;35(7):1284-9. doi: 10.1097/MAO.0000000000000398.

Abstract

Objective: To present a series of patients with facial nerve schwannomas (FNSs) presenting as occluding external auditory canal (EAC) masses.

Study design: Retrospective case series.

Patients: Four patients were identified with mastoid segment FNSs occluding the EAC. Three patients presented with conductive hearing loss (CHL), and the fourth presented with facial paralysis, later developing CHL.

Intervention: One patient underwent conservative debulking, removing the EAC component only. Two patients were managed nonoperatively with periodic cleaning of entrapped keratin. The fourth patient received radiation therapy.

Main outcome measures: Facial nerve function, canal cholesteatoma formation, and hearing.

Results: Among the patients managed with serial cleaning of entrapped keratin, one maintained normal facial function and one worsened to House-Brackmann II/VI. Facial function worsened to House-Brackmann II/VI in the patient who underwent surgical debulking. The fourth patient, who received radiation, developed complete facial paralysis. All patients accumulated keratin medial to the tumor, and all had CHL.

Conclusion: When evaluating an EAC tumor, it is important to obtain imaging before biopsy because biopsy of a schwannoma can result in paralysis. EAC occlusion by a schwannoma presents a challenging management issue, particularly when cholesteatoma forms between the tumor and the tympanic membrane. The primary goal is maintaining normal facial function as long as possible and avoiding secondary ear canal complications. The presence of canal occlusion limits the choice of stereotactic radiation because this leads to a month-long period of tumor swelling and cutaneous sloughing. Resection and grafting are indicated when substantial facial weakness or twitch develops.

MeSH terms

  • Adult
  • Aged
  • Biopsy
  • Child
  • Cholesteatoma / complications
  • Cholesteatoma / pathology*
  • Cholesteatoma / surgery
  • Cranial Nerve Neoplasms / complications
  • Cranial Nerve Neoplasms / pathology*
  • Cranial Nerve Neoplasms / surgery
  • Ear Canal / pathology*
  • Ear Canal / surgery
  • Facial Nerve / pathology*
  • Facial Nerve / surgery
  • Facial Nerve Diseases / pathology*
  • Facial Nerve Diseases / surgery
  • Facial Paralysis / etiology
  • Facial Paralysis / pathology
  • Facial Paralysis / surgery
  • Female
  • Hearing Loss, Conductive / etiology
  • Hearing Loss, Conductive / pathology
  • Hearing Loss, Conductive / surgery
  • Humans
  • Male
  • Neurilemmoma / complications
  • Neurilemmoma / pathology*
  • Neurilemmoma / surgery
  • Retrospective Studies
  • Treatment Outcome