Compressive arachnoid cyst with secondary intracranial hypertension
Presentation
Left hemiparesis.
Patient Data
The MRI sequences demonstrate a large extra-axial cystic lesion measuring (9.5 x 9 x 6.5 cm) of CSF signal on all sequences in the right middle cerebral fossa, extending to the fronto-insular region, compressing the temporal, frontal, and parietal lobes with a mass effect on the midline structures. No restricted diffusion is seen on DWI/ADC.
Prominent subarachnoid spaces around the optic nerves with mild flattening of the sclera bilaterally indicating probably secondary intracranial hypertension.
Case Discussion
MRI features of a large arachnoid cyst type III according to Galassi classification of middle cranial fossa arachnoid cysts with secondary intracranial hypertension.