Large well-defined, infratentorial, extra-axial lesion causing compression effect and anterior displacement of the cerebellum and causing obstructing hydrocephalus.
The lesion appears thick-walled with the hyperintense signal on T1-weighted images and a hypointense signal on T2-weighted images. An internal well-defined area at its dependent portion shows a T1 hypointense rim with signal dropout on SWI.
There is a stalk extension at the posterior aspect of the lesion which is extending through the occipital protuberance and is ending just beneath the skin causing its puckering.