Post-Traumatic Pseudomeningocele Presenting as a Pulsatile Cyst of the External Auditory Canal.

Pseudomeningocele is a of cerebrospinal fluid filled, extracranial cystic collection resulting from a dural defect, which may occur congenitally, postoperatively, or after trauma. Post-traumatic pseudomeningocele is rare, particularly in the temporal bone region. We report a 37-year-old woman who presented with progressive hearing loss and intermittent otorrhea, two decades after head trauma. Otoscopy revealed a pulsatile cystic lesion in the right external auditory canal. Imaging showed a ~20 mm tegmen tympani defect with herniation into the tympanomastoid area. Surgical repair involved transmastoid excision of the sac and multilayer reconstruction of the tegmen defect with mastoid obliteration. This case emphasizes the need to consider skull base defects in patients with a history of head trauma and persistent otologic symptoms.