A colloid cyst is a mass that occurs within the brain that prevents the fluid in the brain from flowing through the ventricles, according to UCLA. Most often, patients have headaches before they have any other symptoms.
Colloid cysts lead to increased brain pressure and may require immediate surgery to eliminate the possibility of sudden death, reports UCLA. The colloid cyst presents in a gooey and gel-like way and usually only occurs in adults, notes the American Brain Tumor Association. It can be difficult to remove colloid cysts because of their location within the brain. As of 2015, it is not known why the colloid cyst develops or how to prevent the colloid cyst or other cysts from developing within the brain.