Presentation
Headache and blurring of vision
Patient Data



A well defined solid lesion is seen occupying and expanding the 4th ventricle. It displays low signal in T1, bright signal in T2 and restricted diffusion in DWI. It shows cystic areas of degenertion inside and extension through the foramina of lushka. Associated supratentorial hydrocephalic changes and CSF transependymal permeation are noted.
Contrast was not administered.
Case Discussion
Although the parents did not consent to IV contrast, DWI helped us to characterize this lesion. 4th ventricular tumors include ependymoma, subependymoma, medulloblastoma and choroid plexus papilloma. The only lesion which may show diffusion restriction is medulloblastoma because it has packed cells (highly cellular tumor).