Technical nuances of the endoscopic resection of a growing third ventricular colloid cyst without hydrocephalus: Two-dimensional operative video

Background: Colloid cysts of the third ventricle are benign epithelial lesions that may enlarge over time and obstruct the foramina of Monro, causing non-communicating hydrocephalus and neurological deterioration. While surgery is well-established in symptomatic patients, the management of asymptomatic growing cysts without hydrocephalus remains a technical challenge, given the reduced ventricular working space and the risk of fornix injury. Prior series suggest that endoscopic resection of incidentally discovered enlarging colloid cysts can be performed safely with favorable outcomes and lower recurrence rates in selected patients. Case Description: This video highlights the case of a 45-year-old male with an incidentally diagnosed colloid cyst of the third ventricle, with documented interval growth in the absence of hydrocephalus. Given the growth, young age, and the potential for future obstruction or symptomatic progression, endoscopic resection was recommended. En bloc resection of the cyst was achieved following careful dissection from the tela choroidea. Gross total resection was confirmed on postoperative imaging, and the patient was discharged on postoperative day 1 with no neurological deficits. Conclusion: This case underscores the technical nuances for safely performing endoscopic resection of a growing colloid cyst of the third ventricle in the absence of hydrocephalus. The patient consented to the procedure and to the anonymized publication of images in accordance with institutional guidelines; therefore, ethical board approval was not required.