[Tumors of the third ventricle: review of 262 cases]

The data from 262 cases of third ventricle (V3) tumors treated in 21 Departments of Neurosurgery in France between 1980 and 1995 were collected in this series. These tumors were frequent in young adults, and 17.5% of the patients were children. Colloid cysts (55%) and gliomas (19%) were the most frequent lesions. Other tumors were rare, or exceptional.

The duration of symptoms was short in time, despite these lesions were usually benign. Most of cases were revealed by intracranial hypertension (63%), sometimes with a paroxystic or positional evolution. Neuropsychological signs (48 %) were undoubtedly under-estimated, revealing the disease in only 10% of cases. Ophthalmologic signs and endocrine disorders were infrequent. This feature is related to the selection of patients in this series, as tumors arising from the floor of the third ventricle or from the optic chiasm were excluded. Endocrine disorders were frequent with gliomas (30 %).

In half of the patients, hydrocephalus was absent or mild and was ruled out after the treatment of the ventricular lesion. However, 12% of patients required a shunt procedure after the treatment of the ventricular lesion. A stereotactic procedure was performed in 63 patients, 12 had ventriculoscopy, and a direct surgical approach to the V3 was performed in 200 patients, sometimes after the failure of stereotactic or endoscopic procedures. Thirty six patients received no treatment. The patients were operated on via a transcortical approach (159 cases), or via the anterior transcallosal route (35 patients). Postoperative course was uneventful in 67% of the patients, complications were recorded in 24% of patients.

The overall mortality in the national series is 13.7 % (36/262 died). The death occurred before any treatment (4 patients), or was directly correlated to the surgical procedure (13 cases), to long-term complications of hydrocephalus (2 patients), to general complications (7 patients), or to recurrence of the tumor (10 cases). The final outcome analysis recorded neurological impairment in 29% of cases, neuropsychological deficit in 50% of patients, and residual endocrine disorders in 19%. Social independence was recovered by 86% of patients, 76% of them returned to work, 72% of students returned to normal school attendance. The long-term neurological outcome was better with the transcallosal approach. No conclusion was possible concerning neuropsychological outcome, as postoperative neuropsychological assessment was not available for most of the patients operated on with the transcortical approach.

The results of treatment were evaluated only for the most frequent lesions (colloid cysts and gliomas). The outcome was worse for gliomas when compared to colloid cysts, considering mortality (13% vs 8%), neurological impairment (36% vs 21%), residual endocrine disorders (34% vs 0%), and ability to return to work (83% vs 56%).