In an accompanying figure, the CT findings in this case are presented. An extra-axial mass lesion is noted, adjacent to and to the left of the falx. The superior sagittal sinus is occluded. Meningiomas with restricted diffusion (hyperintensity on DWI), as in this example, tend to be malignant or highly atypical. The sagittal post-contrast exam reveals the broad base of the lesion along the calvarium, with extension to involve both the skull and the subcutaneous tissue. Despite the extensive spread of disease, by histopathology this was a WHO grade II meningioma.

Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015)