A colloid cyst is a fluid filled sac that forms in the brain, commonly within the lateral or third ventricle. This is a benign cyst, meaning that it is not cancerous. Although these do not spread, they do grow in size which can lead to complications.
Due to the locations of colloid cysts, the flow of cerebral fluid can be compromised. This means that often patients will present with hydrocephalus; this is a build-up of fluid on the brain.
The exact cause of a colloid cyst is still unknown; however, it is thought to be present at birth and therefore develop and grow as the child enters adulthood.
A colloid cyst will often not cause any symptoms until it has grown big enough to affect the flow of cerebral fluid, which will cause hydrocephalus. The symptoms of hydrocephalus include:
Problems with memory
Loss of consciousness (in very rare cases)
A colloid cyst is often found incidentally, meaning that it is found when investigating something else, for example unexplained headaches. This is because there are often no symptoms until the cyst is affecting the flow of cerebral fluid. If it is suspected that you have a brain related condition, your doctor will refer you to have an MRI scan which captures images of the brain and therefore helps your doctor to identify any abnormalities, such as a colloid cyst.
The treatment offered to patients with a colloid cyst will differ depending on the patients’ individual case. If the cyst is not causing any symptoms, it will be left and closely monitored to check on growth annually. If it starts to grow and cause symptoms, treatment may be considered.
If the cyst if affecting the flow of cerebral fluid and leading to hydrocephalus, surgical intervention will be required. The surgery for a colloid cyst is called an endoscopic craniotomy. This is a minimally invasive technique, which involves draining the cyst and removing the cyst wall, so that it does not grow back.
After the surgery if the hydrocephalus is not resolved, a shunt may need to be put in to allow the fluid to flow away from the brain.
This article is intended to inform and give insight but not treat, diagnose or replace the advice of a doctor. Always seek medical advice with any questions regarding a medical condition.