Someone with a colloid cyst will most frequently have no symptoms at all — the slow pace of growth of the cyst allows the brain to compensate for its presence for a long time. That’s one of the reasons why a colloid cyst is often diagnosed incidentally — the cyst can be spotted on a CT or MRI scan done for another reason, such as a work up for headache, sinusitis, or minor head injury.
When a colloid cyst does cause symptoms it is usually because it is blocking the normal circulation of cerebrospinal fluid (CSF). This blockage results in a condition called obstructive hydrocephalus. Headache is the earliest and most common symptom with obstructive hydrocephalus. These headaches can be either mild or severe, and they can be intermittent, making a colloid cyst somewhat difficult to diagnose without imaging.
Headaches are sometimes accompanied by vomiting, which is usually an emergency situation. If the cyst suddenly blocks the flow of CSF, the result can be acute obstructive hydrocephalus, causing an abrupt severe headache and, in rare cases, death.
With longstanding or gradual obstruction of CSF, decline in memory function is another complaint.
Reviewed by: Umberto Tosi, MD
Last reviewed/last updated: September 2024
