Presentation
Epilepsy.
Patient Data
Well-defined left frontal parasagittal mass of extra-axial location measuring 54 X 36 X 34 mm with broad-based dural attachment to the falx cerebri and frontal convexity. It elicits an isosignal to the cortical grey matter on T1, slight high signal on T2 and FLAIR, with vivid enhancement. There is an invasion of the adjacent skull bone and superior sagittal sinus well-visualized mainly on the coronal sequences. A rim of CSF signal around the mass is noted on T2 sequences representing the "CSF cleft sign", indicating its extra-axial location. A mass effect is noted on the adjacent brain with no subfalcine herniation.
Small vessel ischemic changes.
Case Discussion
MRI features of a frontal meningioma invading the skull bone and adjacent segment of the superior sagittal sinus, pathologically proven as atypical meningioma grade II.