[Hyperostosis of the internal auditory canal : An incidental finding?].

In contrast to the fairly common exostoses in the external auditory canal, hyperostoses and osteomas of the internal auditory canal are extremely rare. In this case report we present a patient with sudden right-sided sensorineural hearing loss, in whom imaging revealed hyperostosis with bilateral stenosis of the internal auditory canal. Whether the connection of such radiological findings with dysfunction of cranial nerves VII and VIII be causal or coincidental is controversially discussed in the literature. Therefore, the indication for surgical intervention should be considered with extreme caution. Despite examination of our radiology database comprising almost 1000 MRI/CT temporal bone investigations, we could find no other cases of hyperostosis of the petrous bone. This case thus represents a rare disease, which should be considered a differential diagnosis.