Glial Choristoma in the Middle Ear, A Case Report

The occurance of glial choristoma in the middle ear is extremely rare. A few case reports exist on choristomas in the middle ear. Usually choristoma of the head involves midline structures like nose, nasopharynx or oral cavity.

In our case report a 59 years old female patient presented with left sided progressive hearing loss since a few months. She had a history of cholesteatoma, chronic tube dysfunction and multiple tympanoplasties.

The clinical findings showed a retracted but intact tympanic membrane. A computed tomography showed a new mass in the middle ear, filling the epitympanum and extending to the base of the skull. Intraoperatively after the removal of granulation tissue in the middle ear the incus was arroded. Additionally, a gray polyplike elastic mass was identified starting at the base of the skull and blocking the entire antrum. After removal, a cranial bone defect appeared, without CSF leakage. Histologically, a glial choristoma was detected.

The existing literature shows an increased incidence of middle ear choristomas in connection with previous surgeries, chronic infections or trauma based on an encephalocele. A second group represented a true neuroglial heterotopy without previous associated risk factors. Histologically there was no difference between the entities. Intraoperative visualization of skull base defects, as well as preoperative computed tomography, can provide an indication of the origin and is important to differentiate between the entities, as encephaloceles, especially with CSF leakage, are associated with an increased risk of meningitis and require further therapy.

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Publication History

Article published online:
13 May 2021