Spontaneous onset of CSF otorrhea from a facial canal fistula in an adult: case report.

The purpose of this report is to describe a 64-year-old woman who presented an 8 month history of recurrent spontaneous cerebrospinal fluid leakage into the left middle ear. High resolution computed tomography and computed tomography cisternography showed only a mild protrusion of the tympanic segment of the left facial canal into the ipsilateral middle ear but no definitive fistula. At surgical exploration, cerebrospinal fluid leakage resulted from a fistula in the tympanic segment of the left facial canal. In conclusion, in the adult patient reported herein, the fistula leading to spontaneous CSF otorrhea was identified definitely only intraoperatively. Furthermore, although there were no signs or symptoms of facial nerve dysfunction, it was located in a rare site such as the second segment of the facial canal. When the clinical history, physical examination, and laboratory analysis are strongly suggestive for spontaneous CSF otorrhea, surgical exploration is mandatory even if neuroimaging evaluation is negative or questionable.