Colloid Cysts

Colloid cysts are benign growths in the brain that occur in the third ventricle (a cavity in the brain). They are not true tumors because they do not involve new cell growth but are filled with fluid instead. Although colloid cysts are benign and grow slowly, they can be life threatening because they block the flow of cerebrospinal fluid (CSF). CSF is a clear, watery fluid that surrounds the brain and spinal cord to protect and nourish it. When CSF is blocked, it accumulates and creates pressure in the brain. This condition is known as hydrocephalus.

Symptoms

Symptoms of colloid cysts vary depending on the individual. They may appear gradually as the cyst slowly grows, or abruptly due a sudden blockage of CSF. Common symptoms include headaches, double vision, memory problems, nausea, and vomiting. Severe or sudden fluid blockage can cause comas and even death.

Diagnosis

As with most brain tumors, the first step in diagnosis of a colloid cyst is usually a neurological examination, which checks eye movement and vision, hearing, sensation, reflexes, balance and coordination, motor skills, thinking and memory. After the neurological exam, the doctor may order imaging studies such as CT scans, MRIs, or x-rays to confirm the existence and size of the cyst.

Treatment options

Because the blockage of CSF has such serious consequences, most surgeons treat colloid cysts with surgical removal, which can often be accomplished using minimally invasive techniques. Sometimes the cerebrospinal fluid needs to be drained to relieve pressure on the brain. This can be done either by using a ventricular shunt (a tube from the ventricles that drains the fluid into another part of the body) or through ventriculoscopy. Ventriculoscopy is a minimally invasive surgical technique that drains the CSF without needing to insert a shunt.