Recurrence After Microsurgical Excision of Third Ventricular Colloid Cysts in a Contemporary Cohort of 84 Patients

To examine recurrence rates in patients undergoing microsurgical excision of colloid cysts of the third ventricle with long-term serial clinical and imaging follow-up and to identify risk factors for cyst recurrence.

In this retrospective study, we analyzed a single-surgeon cohort of 84 patients who underwent microsurgical excision of a third ventricular colloid cyst between 1994 and 2018 and who were followed for at least 12 months after surgery. The primary outcome of interest was recurrence (asymptomatic and symptomatic).

The mean age at surgery was 33.8 years (range, 8-65 years). Of 84 patients, 82 (97.6%) were symptomatic and 71 (84.5%) had obstructive hydrocephalus. The mean tumor size was 15.2 mm (range, 7-35 mm). A total or near-total excision was achieved in 76 patients (90.5%). The median clinical follow-up duration was 89.5 months (range, 12-340 months). A total of 81 (96.4%) had follow-up imaging. Overall, recurrence occurred in 25 cases (29.8%), with 7 (8.3%) experiencing symptomatic recurrence. No specific risk factors for recurrence were identified. Longer follow-up was associated with a higher detection of recurrences. The 5-year recurrence free survival rate was 81.6%, which dropped to 66.5% at 10-year follow-up.

Periodic imaging surveillance is essential after excision of third ventricular colloid cysts to detect asymptomatic recurrences because these lesions may recur several years after presumed total or near-total excision. Recurrences associated with clinical symptoms or demonstrated growth on serial follow-up require intervention; however, reoperation may be cautiously deferred in patients with stable asymptomatic recurrences.