{'fraction_non_alphanumeric': 0.02943058221369162, 'fraction_numerical': 0.02815099168266155, 'mean_word_length': 5.085603112840467, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Rate of Recurrence following Stereotactic Aspiration of Colloid Cysts of the Third Ventricle

Background: The rate of recurrence following stereotactic aspiration of colloid cysts is not defined in the literature. Aims: To study the long-term imaging and clinical outcome in patients who had stereotactic aspiration of colloid cysts of the third ventricle. Methods: Between 1987 and 1994, computerized tomography-guided stereotactic aspiration was attempted in 26 consecutive patients with colloid cysts of the third ventricle. Results: There was no mortality or permanent morbidity. A complete aspiration of the cyst was possible in 17 patients, a partial aspiration of the cyst was achieved in 6 and the aspiration failed in 3 patients. On long-term follow-up, symptomatic recurrence was noted in 5/6 patients after partial aspiration and 4/17 patients after complete aspiration (mean follow-up 84.8 months). Kaplan-Meier analysis revealed that after complete aspiration of the cyst, median time to recurrence on imaging is 42 months (95% CI 23.0–60.9 months) but median time to symptomatic recurrence is much later at 184 months (95% CI 88.2–279.7 months). Conclusions: Stereotactic aspiration of colloid cysts remains a valid surgical option as complete aspiration leads to a good long-term outcome in several patients. Partial aspiration of the cyst should be followed by excision of the cyst, due to the high rate of symptomatic recurrence. However, periodic follow-up imaging is mandatory even after complete aspiration as delayed recurrences are possible.