Surgical management of colloid cyst of the third ventricle--a study of 105 cases

Colloid cyst of the third ventricle is a relatively rare intracranial tumor. It generates tremendous interest for the neurosurgeon because of its benign nature, deep location, and an excellent prognosis when diagnosed early and excised.

A retrospective analysis of 105 cases of third ventricle colloid cyst treated between 1967 to 1998 was conducted. The clinical presentation, radiological findings, different surgical approaches, and outcome were analyzed. The transcallosal and transcortical-transventricular approaches were predominantly used. Memory and psychological assessment were carried out both pre- and postoperatively. A computerized tomography (CT) scan was performed during follow-up.

The male to female ratio was 1.5:1. The age of the patients ranged from 10 to 68 years. Headache was the most common symptom. Papilledema and short-term memory disturbances were the most common signs. In 5 patients the colloid cyst was detected incidentally. Surgery for colloid cyst was performed in 93 patients. Transcallosal and transcortical-transventricular approaches were performed in 62 and 30 patients, respectively. In 1 patient the cyst was excised through the subfrontal lamina terminalis approach. Total excision was achieved in 90 patients, while partial cyst excision was done in three patients. Moderate to severe lateral ventricular enlargement was found in 76 patients at presentation. A ventriculoperitoneal shunt was the only surgical procedure performed in 7 patients. In 16 patients colloid cyst excision was conducted after cerebrospinal fluid (CSF) diversion via a shunt. No surgical treatment of any kind was performed in 5 patients. Five patients died. Eighty-six patients came for follow-up, with a range from 1 month to 25 years (average 3 years and 8 months). Postoperatively, transient recent memory deficits occurred in 14 patients, while a permanent recent memory loss was noted in 2 patients. There was no incidence of postoperative disconnection syndrome or behavioral disturbance. A CT scan was performed in 44 patients during follow-up. Recurrence was detected in 1 patient in whom the cyst had been partially excised.

Colloid cyst, although a benign tumor, is surgically challenging because of its deep midline location. Early detection and total excision of the colloid cyst carries an excellent prognosis.