Abstract
A 2-year-old boy underwent right myringotomy, during which a clear fluid gushed out of the ear. The next day, the child developed meningitis. Computed tomography and magnetic resonance imaging revealed inner ear anomalies in form of Mondini's dysplasia and bilateral vestibular aqueduct enlargement. Right exploratory tympanotomy revealed a cerebrospinal fluid gusher and cystic lesion filling the entire middle ear space. Complete excision of the sac and obliteration of the defect were achieved. To the best of our knowledge, this is the first report of a sac originating in the inner ear and herniating into the middle ear causing cerebrospinal fluid otorrhea.