Citation, DOI, disclosures and case data
Work-up for right-sided hearing loss.
There is a heterogeneous intermediate to hyperintense intense T2 signal mass centered at the right cerebral pontine angle cistern extending into the right internal auditory canal along the course of the 7th and 8th cranial nerve complex. This demonstrates heterogeneous enhancement, noting some central regions of nonenhancement. The component of the mass within the cerebral pontine angle cistern measures approximately 2.4 x 1.6 x 2.6 cm (AP x TV x CC) with additional tumoral component extending medially into the right internal auditory canal by up to 0.7 cm. The lesion has mass effect upon the adjacent right lateral margin of the pons, right brachium pontis, and anterior aspect of the right cerebellar hemisphere. Superiorly, the lesion has some mass effect upon the right trigeminal nerve at its root entry zone. Inferiorly, the mass likely contacts the right 9th, 10th, and 11th cranial nerves. There is partial effacement of the fourth ventricle related to mass effect on the right side of the posterior fossa. Otherwise, there is no hydrocephalus.
The left 7th and 8th cranial nerve complex are normal in appearance. No mass is identified at the left cerebellopontine angle cistern or internal auditory canal.
There are couple of small foci of T2/FLAIR hyperintensity within the posterior left periventricular, which may be related to minimal microangiopathic changes.
This is a case of a vestibular schwannoma. The patient underwent a right retro-sigmoid approach for resection of the tumor which revealed tan-pink, soft tissue on gross pathologic examination. Histopathologic findings were consistent with a vestibular schwannoma with areas of cystic degeneration.