[Two cases of facial neurinoma successfully treated with gamma knife radiosurgery].

Two cases of facial neurinoma successfully treated with gamma knife radiosurgery are reported. Case 1, a 33-year-old female, developed a right-sided hemifacial spasm about five years ago. Then she suffered gradual progression of right-sided facial palsy, dysgeusia and reduction of lacrimation, but she had no hearing disturbance. T1-weighted MRI with gadolinium DTPA showed a well-circumscribed tumor at the geniculate ganglion extending to the middle cranial fossa. The tumor was treated with gamma knife radiosurgery which reduced its size, but didn't reduce the patient's facial palsy. Case 2, a 36-year-old female, presented with fluctuating facial palsy and sensorineural hearing loss lasting for fourteen years. T1-weighted enhanced MRI showed a well-enhanced tumor at the CP angle extending to the middle cranial fossa. The tumor was treated with gamma knife radiosurgery, which caused central tumor necrosis, but didn't reduce the tumor size. Meanwhile the patient's facial palsy improved. Gamma knife radiosurgery is apparently effective against facial neurinomas without producing serious complications such as complete facial palsy and hearing loss. Our study indicates that gamma knife radiosurgery is a useful therapeutic alternative for facial neurinomas.