An extra-axial expanding lesion occupies the right cerebellopontine angle, extends into and funnels the right internal auditory canal.
The lesion invaginates the right side of the pons, right middle cerebellar peduncle and anteromedial part of the right cerebellar hemisphere.
The fourth ventricle is displaced to the left side and compressed.
The lesion measures 4.7 x 4.0 x 4.0 cm (side to side, A.P and cephalo-caudal maximal diameters). It shows multiple different sized cystic changes.
Following injection of contrast, the lesion shows heterogeneous enhancement.
DWI revealed no diffusion restriction of the tumour and its contained cystic changes.
Incidentally noted small right paramedian posterior fossa arachnoid cyst.