Presentation
Headache
Patient Data
Age: 20 years
Gender: Female
From the case:
Arachnoid 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/122268/annotated_viewer_json?_c=1721842106\u0026lang=us"}
Large CSF density lesion in the left cerebellopontine angle causing mass effect on the adjacent left middle cerebellar peduncle suggestive of an arachnoid cyst.
Case Discussion
The arachnoid cysts are usually small and asymptomatic. On CT scan they are well-defined masses of CSF density with imperceptible walls and cause mass effect on the adjacent structures. They can also cause scalloping of the adjacent bone.