Ependymoma, supratentorial

44-year-old male with new onset seizures. There is a partially circumscribed, predominately solid, T1-hypointense, T2/FLAIR-hyperintense left parietal lobe mass which enhances and also restricts diffusion. The lesion involves both the cortical gray matter and subcortical white matter. There is peripheral vasogenic edema which extends to the ependymal/subependymal margin at the body of the left lateral ventricle. The differential includes oligodendroglioma, astrocytoma, and ganglioglioma. On biopsy, this was found to be a supratentorial ependymoma. Supratentorial ependymomas account for approximately 40% of all ependymomas. While supratentorial ependymomas may be intraventricular, at this location, they are usually intraparenchymal lesions. They are thought to arise from radial glial stem cells.