Typical imaging features of an acoustic schwannoma: extension and expansion of the IAC (ice-cream cone appearance), cystic degeneration, and likely microhaemorrhagic foci.  

Microscopic description: the sections show a moderately cellular schwannoma. It mainly contains Antoni A areas with fascicles of spindle cells. There is focal palisading but Verocay body formation is inconspicuous. The tumor cells show no significant nuclear pleomorphism. There are abundant foamy macrophages in the stroma. No evidence of malignancy is identified.

Diagnosis: brain tissue: schwannoma.