Cerebrospinal fluid leak of the fallopian canal.

Spontaneous cerebrospinal fluid (CSF) leaks from the fallopian canal are extremely rare, as only a few cases have been reported in the world literature. We describe a case of spontaneous CSF otorrhea through an enlarged geniculate fallopian canal. The patient was a 45-year-old woman who presented with a history of CSF rhinorrhea and otorrhea from the right ear. Myringotomy and tube insertion revealed CSF otorrhea. Contrast-enhanced computed tomography revealed that the geniculate fossa was smoothly enlarged (demonstrating remodeling of bone). A middle fossa craniotomy with temporal bone exploration was performed. Intraoperative inspection detected the presence of a fistula secondary to a lateral extension of the subarachnoid space through the labyrinthine segments of the fallopian canal. We discuss the management of this unusual finding, which involves sealing the fistula while preserving facial nerve function.