[Misdiagnosis of facial never tumor]

To analyze the misdiagnosis of facial nerve tumor and better understand facial nerve tumor.

Twenty-eight patients with facial nerve tumor were undergone surgical treatment during January 1993 to September 2006. Eleven patients had been misdiagnosed. All patients were undergone pure tone audiometry, CT scan or MRI. Facial nerve function was evaluated with House-Brackmann grading system.

Eleven cases were misdiagnosed. Two cases were misdiagnosed as parotid tumor preoperatively. They were identified as facial never tumor because the masses originated from facial nerve during the surgery and confirmed by pathological examination. Four cases with unilateral facial nerve paralysis lasting from one year to eight years had been misdiagnosed as Bell palsy. Two cases with recurrent facial nerve palsy were misdiagnosed as Bell palsy. Finally MRI and CT demonstrated a mass at the genicular segment of facial nerve. One case with hearing loss and mass in external acoustic meatus was misdiagnoses as external acoustic meatus neoplasm. It was verified as facial schwannomas by biopsy and CT scan. One case with ear discharge, tympanic membrane perforation, soft tissue mass at epitympanum was misdiagnosed as chronic suppurative otitis media, lump was found close to the horizontal segment of facial nerve intraoperatively, and then it was confirmed as facial schwannomas by pathology. One case with soft tissue mass at mastoid and facial paralysis lasting about one and a half years was misdiagnosed as congenital cholesteatoma preoperatively. After admission, MRI study revealed the mass was involved in the facial nerve and parotid gland, and facial nerve tumor was suspected. All the 11 cases were undergone surgery, and the diagnosis was confirmed pathologically.

Facial nerve tumor was rare and unfamiliar with most of Otologists. The present study showed that the three symptoms or signs should be alert: patient presents with facial paralysis does not partially recovered within six months or patient presents with recurrent facial paralysis, CT scan and MRI should be ordered for these patients to rule out space-occupation along facial nerve. Soft tissue mass associates with the horizontal or vertical segment of facial nerve should be distinguished with Cholesteatoma and otitis media while patient complains of facial paralysis. Parotid neoplasm close to facial nerve should be considered it originates from facial nerve.