label: Third ventricle colloid cyst
label_lc: third ventricle colloid cyst
description: "An epithelial lined cyst filled with gelatinous material. The gelatinous material commonly contains mucin, old blood, cholesterol, and ions. Most colloid cysts identified are currently asymptomatic and identified incidentally on imaging. When a colloid cyst does cause issues, it most commonly causes obstructive hydrocephalus."