[Microscopic excision of a colloyd cyst of the third ventricle assisted by endoscopy. Case report and literature analysis.]

Introduction: Colloid cysts are histologically benign lesions, probably derived from the endoderm, which represent 0.3-2% of brain tumors. They are usually attached to the roof of the third ventricle in direct relation to the foramen of Monro, which can cause a blockage to the circulation of cerebrospinal fluid, determining hydrocephalus and in some cases sudden death. Other more common symptoms are headache, nausea and vomiting, blurred vision, gait ataxia, and cognitive impairment. Treatment options include microsurgery, endoscopy, stereotaxic casting, or cerebrospinal fluid shunts for the treatment of hydrocephalus. The objective of surgery is the total excision of the lesion. It should be noted that the microsurgical technique allows total excision more frequently, but at the cost of greater manipulation and tissue trauma; on the contrary, endoscopic being minimally invasive, allows better tissue preservation, although the rates of complete tumor excision are usually lower due to the difficulties in dissecting the lesions densely adhered to the roof of the third ventricle.

Method: We present a clinical case of a patient with a third ventricle tumor compatible with a colloid cyst, with progressive hydrocephalus, operated with microsurgical technique and endoscopic assistance.

Result: Total excision of the colloid cyst with improvement of the symptoms. Antegrade memory disorder that resolved completely after 3 months.

Conclusion: The endoscopy-assisted microsurgical technique is safe for the management of this pathology and provides intraoperative benefits.