Colloid cysts of the third ventricle

Abstract

✓ Thirty-eight cases of colloid cyst of the third ventricle are reviewed. Headache was the most frequent complaint but a strong positional relationship, supposedly a pathognomonic feature of this tumor, was seldom seen. A combination of progressive dementia and gait disturbance without evidence of papilledema, resembling the clinical picture in “normal-pressure” hydrocephalus, was present in eight patients. Sudden deterioration and death occurred in four cases; two other deaths were precipitated by lumbar puncture and pneumoencephalography. Ventriculography was the most reliable diagnostic study. Both the demonstration of dilatation of the lateral ventricles and an upward convexity in the initial segment of the internal cerebral vein in five of the 10 angiograms performed were highly suggestive of tumor. Removal of the colloid cyst through a cortical incision in the non-dominant hemisphere was carried out in 21 cases; in six it was necessary to enlarge the foramen of Monro by dividing the ipsilateral anterior column of the fornix. There were three deaths in the early and two in the late postoperative period. The main complication associated with the transventricular approach was the development of seizures.