Presentation
Head trauma.
Patient Data
Large well-circumscribed cystic lesion of extra-axial location in the left middle cranial fossa, extending to the insular region with a mass effect on the temporal and frontal lobes with thinning of the adjacent inner table of the skull. No significant mass effect on the midline structures.
No extra-or subdural hematoma nor parenchymal contusion or subarachnoid hemorrhage.
No cranial vault or skull base fracture.
Case Discussion
CT features of a large arachnoid cyst of the middle cranial fossa extending to the insular region, type III according to Galassi classification (incidental finding in this case).