Subependymal giant cell astrocytoma: Neuroimaging features of 2 cases

The neuroimaging, as well as clinical features of 2 patients with histologically verified subependymal giant cell astrocytomas (SEGAs) are presented. Case 1, a 7-year-old boy, was admitted because of sequential neuroimaging studies over 6 years revealing the growth of 'subependymal nodules' into intraventricular tumors. In case 2, headache related to raised intracranial pressure was the first and only sign. In each case the tumor was in the region of Monro's foramen and was associated with ventricular dilatation. In addition to SEGAs, which were markedly enhanced by contrast medium, multiple subependymal nodules were found on CT in both patients. On MRI, one SEGA was isointense with the cerebral cortex and the other with the white matter on T1-weighted images, and both tumors were isointense with the cortex on T2-weighted images. At surgery, the tumors appeared to originate from the inferolateral wall of the lateral ventricle in the region of the head of the caudate nuclei. The clinical and neuroimaging features are discussed with periodic monitoring with neuroimaging studies being recommended even for asymptomatic patients with 'subependymal nodules'.