Risk Analysis and Management of Third Ventricular Colloid Cysts.

OBJECTIVE: Colloid cysts (CCs) are histologically benign lesions that carry the risk of causing obstructive hydrocephalus. The indication for surgery for symptomatic cysts is unquestioned; however, the management of incidentally detected lesions has remained controversial. We independently evaluated the CC risk score (CCRS) as a useful risk stratification scheme.

METHODS: The demographics, imaging characteristics, and clinical presentations of 103 patients with CC during a 10-year period were correlated with symptoms and the occurrence of hydrocephalus. The discriminate capacity of the CCRS was quantified and a decision algorithm formulated.

RESULTS: The correlates of symptoms included age <65 years, diameter ≥7 mm, anterior location, hyperintensity on T2-weighted fluid-attenuated inversion recovery (FLAIR) and/or T2-weighted images, and headache at presentation without an alternative explanation. On multivariate analysis, age <65 years, diameter ≥7 mm, and headache at presentation predicted for symptomatic cysts. The CCRS was highly effective at identifying symptomatic patients and those with obstructive hydrocephalus. All patients with cyst growth and symptomatic progression had had an initial CCRS of ≥3 plus hyperintensity (preexisting or developing) on T2-weighted FLAIR images.

CONCLUSIONS: The CCRS performed exceptionally well in distinguishing the highest risk patients. Closer follow-up is recommended for younger asymptomatic patients with cysts near the foramen of Monro. Hyperintensity on T2-weighted FLAIR images might indicate greater growth potential for small lesions.