Abstract
An eight-year-old female, known to have sensorineural hearing loss due to inner ear anomalies, presented with a history of recurrent attacks of right acute otitis media complicated by bacterial meningitis. Temporal bone computed tomography showed right middle ear and mastoid effusion without bony dehiscence or erosion, with features of common cavity inner ear anomaly on the right side. Given the patient's inner ear malformation, cerebrospinal fluid (CSF) otorrhea was suspected. Further evaluation with myringocentesis and beta trace protein analysis confirmed the diagnosis. The patient underwent transcanal endoscopic right ear exploration. Initially, the site of the defect was not revealed; the CSF leak was successfully localized at the oval window, surrounding the stapes footplate. This is the first report, to the best of our knowledge, describing topical fluorescein application in a transcanal endoscopic approach to obliterating CSF otorrhea due to inner ear malformation.