What is a colloid cyst?
Colloid cysts compose 0.5 – 1% of intracranial tumors. They arise from cells which are so-called “neuroepithelial” meaning that they arise from primitive cells during development. Colloid cysts are usually located in the anterior portion of the third ventricle in which location they can block the outflow pathways for the cerebrospinal fluid and cause water in the brain (hydrocephalus). Some colloid cysts are also located in the septum pelucidum. What are the symptoms? The signs of a colloid cyst include acute intermittent hypertension within the head due to sudden blockage of CSF flow with sudden increase in the volume of intraventricular water (remember that ventricular cerebrospinal fluid is produced at a rate of 500cc/day). There is a syndrome of sudden death associated with acute obstruction of the CSF circulation pathway due to herniation of the brain with possible compromise of the cardiovascular control center of the hypothalamus. How is it diagnosed? The diagnosis of colloid cy
