Microsurgical Outcomes of Third-Ventricle Colloid Cysts Treated via an Interhemispheric Transcallosal Approach: Clinical and Imaging Correlates in a Retrospective Single-Center Series.

[OBJECTIVE] Colloid cysts of the third ventricle are rare, benign lesions that can lead to acute cerebrospinal fluid obstruction, rapid neurological deterioration, and sudden death. This study aimed to evaluate the clinical presentation, imaging characteristics, and postoperative outcomes of surgically treated third-ventricle colloid cysts, with emphasis on imaging correlates and age-related patterns of clinical presentation.

[METHODS] We retrospectively analyzed 25 consecutive patients who underwent microscopic interhemispheric transcallosal excision of third-ventricle colloid cysts between 2008 and 2023, assessing demographic, clinical, imaging, and postoperative variables, including magnetic resonance imaging characteristics, ventricular parameters, and Colloid Cyst Risk Score (CCRS) classification.

[RESULTS] The median age was 35 years (interquartile range, 22-46), and 96% of patients were symptomatic, most commonly presenting with headache (92%). All cysts were located in CCRS risk zone I, and all patients had CCRS scores ≥4. Fluid-attenuated inversion recovery hyperintensity was observed in 72% of cases, and ventricular asymmetry in 48%. Patients aged ≥40 years exhibited significantly longer symptom duration and larger cyst diameter, with a moderate positive correlation between age and cyst diameter (P = 0.015). Gross total resection was achieved in all cases. Postoperative shunt dependency occurred in 8%, complications in 8%, and reoperation due to imaging-confirmed recurrence in 4%. Median postoperative follow-up was 13 months (interquartile range, 8-70).

[CONCLUSIONS] Microscopic interhemispheric transcallosal excision appears to provide safe and effective management of third-ventricle colloid cysts, with high rates of complete resection and low morbidity in this single-center series. Preoperative risk assessment supported by CCRS and magnetic resonance imaging findings may help contextualize symptomatic risk and guide clinical decision-making.