[Computed tomography in the diagnosis of intracranial trigeminal neuroma].

CT scans of 12 cases of intracranial trigeminal neuroma were presented. Three of the neuromas were located in petrous apex-middle cranial fossa, two in posterior cranial fossa, and 7 in both the middle and posterior cranial fossae. The tumors appeared hypo- and isodense on the plain CT scan. After contrast infusion, all tumors were well circumscribed with marked enhancement, which was homogeneous, inhomogeneous or circular. None of the trigeminal neuroma had surrounding brain edema. Of 12 cases, 10 showed change of cranial bones, which included dilatation of Meckle's cave and destructions of petrous apex, clivus and the bottom of middle cranial fossa. The tumor in one case extended to paranasopharyngeal space from the bottom of middle cranial fossa, Various features of trigeminal neuroma on CT were reviewed. Also presented were the author's experiences in differentiating intracranial trigeminal neuroma from meningiom, from pituitary adenoma spreading to parasella and glioma adjacent to cranial bottom in middle cranial fossa, and from acoustic neuroma, meningioma, cholesteatoma in cerebellopontine angle.