Computed tomography of intracranial ependymomas.

It appears reasonable to suggest a histological diagnosis of ependymoma when CT shows an isodense tumor expanding the fourth ventricle or lying within its outlets; when the tumor contains small, round calcifications; and when presentation occurs early in life. An isodense mass occurring in the cerebral white matter, containing a cyst, exhibiting small, round calcifications, and developing early in life should also suggest the diagnosis. Unfortunately, despite a high accuracy of detection (95%) and the use or modern therapeutic modalities, the outcome remains poor.