Extracranial meningioma presenting as a tumour of the external auditory meatus: a case report.

A rare case of extracranial meningioma presenting as a tumour of the external auditory meatus is reported. Biopsy indicated a diagnosis of meningioma, but the radiological appearance was unusual. For example, computed tomography (CT) scans showed an unenhanced tumour mainly located in the squamous part of the temporal bone which expanded into the external meatus destroying the temporal bone. Magnetic resonance imaging (MRI) revealed that the tumour did not extend into the intradural space. This meningioma, had an obvious tendency for extracranial development. According to the operative findings, the tumour arose from the middle cranial fossa dura and extended through the air cells of the temporal bone into the external meatus, instead of growing intracranially. Secondary extracranial meningiomas of the temporal bone usually have a large intracranial component and cause neurological symptoms. However, this was a very rare case of a small meningioma causing no symptoms except for conductive hearing loss.