Computed tomography in the diagnosis of primary tumors of the petrous bone.

This paper constitutes an evaluation of 23 patients with signs and symptoms of 4 types of tumors: 6 congenital epidermoids, 3 cases of meningiomas presenting within the temporal bone, 2 cases of jugular fossa schwannomas, 3 cases of glomus tympanicum, and 9 selected cases of glomus jugulare tumors. Since these tumors occur insidiously and are located in an inaccessible region of the skull, they are usually not diagnosed until they reach considerable size and cause multiple cranial nerve deficits or intracranial complications. Assessment of these tumors and subsequent surgical management depend primarily on the preoperative radiographic findings. CT and dynamic CT study have proven to be extremely valuable and accurate in the diagnosis of these lesions. Epidermoids have a characteristic CT appearance. Dynamic CT is often helpful in differentiating glomus tumors from meningiomas and schwannomas. Involvement of the middle ear, labyrinth, intracranial, and extracranial components of these tumors can be best evaluated by CT. This paper places special emphasis on congenital cholesteatoma (epidermoid) and draws relevant conclusions about the diagnostic work-up.