Large basal ganglia cyst in site of previously radiated glioma. Case report.

A 3 1/2-year-old boy developed a mass lesion in the right basal ganglia and midbrain, compatible with glioma. During radiation therapy, aqueduct obstruction developed, necessitating a ventriculoatrial (VA) shunt. The child improved and remained well for 6 years, when he developed recurrent symptoms. A computerized tomographic (CT) scan and ventriculogram revealed a large cyst arising from the region of the right basal ganglia, the site of the previous tumor. The VA shunt was converted to a cyst atrial shunt. Subsequently, the cyst decreased in size, but hydrocephalus recurred, as demonstrated by a second CT scan. A Y-tube shunt (one catheter in the cyst, one in the ventricle) has controlled symptoms and signs since that time.