Arachnoid cyst within the fourth ventricle: a case report.

The authors report a case of fourth ventricular arachnoid cyst that presented clinically with the criteria of normal pressure hydrocephalus. Only a few cases of intraventricular arachnoid cyst have been recorded in the literature. In our case, a posterior approach was used via a midline suboccipital craniectomy and the cyst was excised.