[Facial nerve neurinoma--report of 2 cases]

Two cases of facial nerve neurinoma (VII-Nm) were reported. The first case is a 41-year-old man who had 16 years of history of slowly progressive right facial palsy and hearing disturbance. The tumor originated in horizontal portion of the right facial nerve, and extended epidurally into the middle cranial fossa, as well as medially along the facial canal to the C-P angle. The second case is a 55-year-old man with 16 years of history of progressive right facial palsy which was followed by hearing disturbance. The tumor was found in the vertical portion of the right facial nerve, expanding in the petrous bone. Both tumors were removed surgically. 116 VII-Nm were reported in the literature including our 2 cases. Most were reported in the ENT field, and only 11 cases in the neurosurgical field. Facial palsy or hearing disturbance is the initial symptom, depending on the site of origin in the facial nerve. VII-Nm can originate in any part of the facial nerve. The most common part of origin is the vertical portion where the tumor tends to expand locally, but it may extend extracranially along the facial canal. The tumor which originates in the tympanic portion tends to extend into the middle ear cavity. The tumor originating in the horizontal portion extends to the epidural space in the middle cranial fossa and/or medially along the facial canal. VII-Nm in the cisternal portion of the facial nerve extends to the posterior cranial fossa and produces the signs of C-P angle tumor. Unlike the acoustic neurinoma, VII-Nm is associated with marked facial palsy.(ABSTRACT TRUNCATED AT 250 WORDS)