Endoscopic resection of incidental colloid cysts

Abstract

Object: Incidental colloid cysts are frequently managed with surveillance imaging rather than surgical excision. This approach is born out of their purported indolent growth pattern and the surgical morbidity associated with microsurgical removal. The advent of endoscopic colloid cyst removal may offer renewed assessment of these patients who carry a risk of acute neurological deterioration. An evidence-based recommendation should weigh the risks of operative treatment. Thus far, there has been no concentrated assessment of cyst removal in patients with incidental colloid cysts. The major objective in this study was to define the risks associated with the endoscopic surgical removal of incidentally diagnosed colloid cysts.

Methods: A retrospective review of the medical records was performed to search for patients evaluated for a colloid cyst between the years 1996 and 2012. Eighty-seven patients underwent colloid cyst resection, and 34 were managed with nonoperative surveillance imaging. Microsurgical resections, endoscopic resections of residual or recurrent colloid cysts, and cases with unknown preoperative symptomatic status were excluded from further analysis. Seventy-seven cases of primary endoscopic resections were identified. Twenty resections were performed in patients with an incidental diagnosis and 57 in symptomatic individuals. Presenting characteristics and surgical outcomes were compared between the incidental and symptomatic groups.

Results: The mean age at surgery was 39.65 years for the incidental and 43.31 years for the symptomatic group (p = 0.36). The median maximal cyst diameter was 9.7 mm (range 3-31 mm) for the incidental and 12 mm (range 5-34 mm) for the symptomatic group. The mean frontal and occipital horn ratio was 0.3928 for the incidental and 0.4445 for the symptomatic group (p = 0.002). Total resection was achieved in 90% of the incidental and 82.3% of the symptomatic cases (p = 0.49). The median hospital stay was 1 day for incidental and 2 days for symptomatic cases (p = 0.006). There were no deaths. There was one case of aseptic meningitis in the incidental group. In the symptomatic group there were 3 complications: one patient with subjective memory impairment, one with transient short-term memory deterioration, and another with a superficial wound infection treated with operative debridement. Two patients from the symptomatic group needed a CSF diversion procedure, and no shunting was needed in the incidental group. There were two recurrences in the symptomatic group (78 and 133 months postoperatively) and none in the incidental group (p = 1).

Conclusions: Age and cyst diameter were not correlated with the absence or presence of symptoms in patients with a colloid cyst of the third ventricle. Operative results were highly favorable in both groups and did not reveal a higher risk of morbidity in the patient presenting with an incidental lesion. The results support endoscopic resection as a legitimate therapeutic option for patients with incidental colloid cysts. Generalization of the operative results should be cautiously made, since this is a limited series and the results may depend on the degree of neuroendoscopic experience.

Keywords: ENT = ear nose and throat; EVD = external ventricular drain; FOR = frontal and occipital horn ratio; asymptomatic disease; colloid cyst; incidental finding; neuroendoscopy; oncology; third ventricle; treatment outcome.