What is your differential at this point?
Differential includes a neoplasm (astrocytoma, metastasis, Lhermitte Duclos), subacute infarction, demyelination (tumefactive) and even infection.
A large, heterogeneous, non enhancing and non-calcified right cerebellar mass compresses and distorts the fourth ventricle with resultant dilatation of the third and lateral ventricles and tonsillar herniation.There is no appreciable contrast enhancement following administration of contrast.