9-year-old male status post trauma. In the right cerebellopontine angle, there is a low density lesion approximating CSF attenuation consistent with an arachnoid cyst or epidermoid cyst. This lesion causes surrounding bony remodeling, however there is no evidence of bony destruction. There is mild mass effect upon the cerebellum, however no edema is noted in the adjacent brain parenchyma. A follow-up MRI is recommended for further evaluation. The remainder of the cerebral and cerebellar hemispheres and brainstem are normal in morphology and attenuation. No intracranial hemorrhage or edema is noted. The ventricles and basal cisterns are normal in size and configuration. The calvaria and skull base are radiographically normal. The visualized paranasal sinuses and mastoid air cells are normally pneumatized.
Right cerebellopontine angle arachnoid cyst or epidermoid cyst. An MR is recommended for further evaluation. These findings were discussed with Dr. Amanda Johnson at 11:25 a.m. on 8/26/08.