Stereotactic techniques for colloid cysts: roles of aspiration, endoscopy, and microsurgery.

Stereotactic surgical techniques were used to manage 25 consecutive patients with colloid cysts of the third ventricle. All patients had stereotactic aspiration as the initial procedure; it was successful in 13 (52%). In patients in whom aspiration failed, endoscopic visualization of the cyst and attempted removal, or microsurgical cyst resection via a transcortical approach was performed. Three elderly patients did not have a second procedure and were shunted. The computed tomographic appearance of a hypodense or isodense cyst indicates low-viscosity contents and predicts successful stereotactic aspiration. Stereotactic microsurgery is used in hyperdense cysts, or in those which cannot be aspirated.