CT-stereotaxic drainage of colloid cysts in the foramen of Monro and the third ventricle.

Colloid cysts in the foramen of Monro and third ventricle account for 0.5% to 1% of all intracranial space-occupying lesions. The introduction of computerized tomography (CT) and magnetic resonance imaging has represented a major advance in the early detection of these cysts. The risks associated with the management of benign space-occupying lesions by open surgical procedures have made it necessary to search for safer techniques. The CT-stereotaxic method provides a simple, precise, and safe method of puncturing deep-seated space-occupying cysts. Between January, 1979, and December, 1984, 12 patients with colloid cysts in the foramen of Monro and third ventricle were operated on by this method. The operations were successful, and there were no intraoperative or postoperative complications. The advantages of the CT-stereotaxic method are discussed and the results are presented.