Neuroradiology

Subependymoma

an unusual, benign, highly differentiated CNS tumour with distinctive histology, consisting of astrocytes and ependymal cells. It is considered to be a variant of ependymoma and may represent a transitional form between ependymomas and astrocytomas. These tumours are usually sharply demarcated, intraventricular masses with preferential location in the inferior fourth ventricle and in the frontal horns, developing from the subependymal region.

They are rare in children and occur mainly in middle-aged and elderly adults. Symptoms are usually due to impaired CSF circulation and hydrocephalus.

MR shows an intraventricular mass, iso-hypointense on T1-weighted images and hyperintense on T2-weighted images, usually without enhancement. The differential diagnosis include ependymoma, central neurocytoma, intraventricular meningioma and choroid plexus tumour.

GS