What two entities do you favour?
The differential is between an ependymoma and medulloblastoma. Although features are indeterminate, the mass appears to arise form the vermis and presence of significant supratentorial deposits and restricted diffusion favour a medullobastoma, whereas extrusion through the foramen of Luschka and calcification somewhat favour ependymoma.
MRI confirms a mass arising from or invading the vermis. It is isointense to T1 and hyperintense on T2 with restricted diffusion, consistent with a cellular histology. Only faint contrast enhancement is present.
The mass appears to extend through the foramen of Luschka.
A number of similar signal intensity lesions are scattered throughout the rest of the intracranial cavity, including supratentorially: left middle cranial fossa, pinal region, third ventricle, quadrigeminal cistern.