Clinical question: History of acoustic schwannoma status post chest SRS. Signs and symptoms: Surveillance. Pre- and post enhanced MRI of IAC:Examination redemonstrate an expansile schwannoma within the left internal auditory canal and with significant expansion into the left cerebellopontine angle cistern. Similar to prior exam the mass demonstrates intense enhancement and with a small focus of hypoenhancement in its cerebellopontine angle segment.Similar to prior exam the tumor occupies entire left IAC and with resultant significant expansion.The largest transaxial dimensions of the entire tumor measures at 25 x 27 mm compared to prior study remeasurement of 22.7 x 27 mm.The widest AP axis of the left internal auditory canal measures at 14 mm compared to prior study measurement of 12.5 mm. There is also suggestion of slight further bony remodeling of the dorsal edge of the left IAC. Constellation of above findings/measurements suggests subtle interval increased size of lesion and closer follow-up is recommended.
Revisualization of a large left intracanalicular and cerebellopontine angle schwannoma as detailed/measured above. Findings suspicious of mild interval increased size of lesion as detailed/measured above. 