Presentation
Incidental finding.
Patient Data
Age: 3 years
Gender: Male
From the case:
Blake's pouch cyst
{"current_user":null,"step_through_annotations":true,"access":{"can_edit":false,"can_download":true,"can_toggle_annotations":true,"can_feature":false,"can_examine_pipeline_reports":false,"can_pin":false},"extraPropsURL":"/studies/115612/annotated_viewer_json?iframe=true\u0026lang=us"}
Cystic structure of CSF signal on all sequences with no restricted diffusion, located below and posterior to the vermis and communicating with an open 4th ventricle. No vermian hypoplasia or rotation. No significant dilatation of the 4th ventricle or supratentorial ventricles.
Case Discussion
Blake's pouch cyst represents posterior ballooning of the inferior medullary velum into the cisterna magna, located below and posterior to the vermis and communicating with an open 4th ventricle. It is caused by a failure of the regression of Blake's pouch due to the non-perforation of the foramen of Magendie