Weill Cornell Neurological Surgery

Colloid Cyst Surgery

Colloid cysts of the third ventricle are rare tumors that form inside one of the fluid-filled cavities (ventricles) of the brain. Worldwide, colloid cysts represent only one half to one percent of all brain tumors.

Although they are benign, colloid cysts sometimes block the circulation of cerebrospinal fluid (CSF), causing intracranial pressure and, rarely, sudden death. They more commonly cause hydrocephalus ("water on the brain"), leading to headache, nausea and vomiting, double vision, or seizures. Other patients develop memory disturbances or behavioral problems. Some colloid cysts cause no apparent signs or symptoms at all, and are only discovered when a patient has a CT or MRI scan for unrelated reasons.

How and whether to treat a colloid cyst is based upon a number of factors, including the patient's age, the type and severity of the symptoms, and the details of what we see on the MRI. If a patient has no symptoms, treatment may not be needed at all, since these lesions grow very slowly. When treatment is needed, surgery is the best option, since it cures the condition and has the added benefit of re-establishing normal internal drainage of CSF within the brain.

There are two main surgical techniques for colloid cyst removal:

Craniotomy for Microsurgical Removal:

Before the advent of endoscopic neurosurgery, the removal of a colloid cyst required a craniotomy. This traditional treatment has been used for several decades and is still the most common surgical approach. In this procedure, the neurosurgeon creates an opening in the skull (a craniotomy) and uses small instruments to remove the colloid cyst. This procedure is performed under general anesthesia and takes several hours; it requires several days of a hospital stay.

Endoscopic (Minimally Invasive) Resection:

This contemporary procedure relies on the use of endoscopes through a much smaller opening (less than half an inch) in the skull. The opening is just behind the hairline and requires negligible hair removal, so it's barely noticeable afterward. The neurosurgeon inserts an endoscope through this opening, into the ventricular compartment of the brain, and to the surface of the tumor. The wall of the tumor is coagulated with an electrical current, and the cyst is then opened. A variety of suction catheters empty the contents of the cyst, then the cyst wall is removed and any remnants destroyed using an electrical current. The endoscope is removed and the neurosurgeon closes the incision. This surgery is also performed using general anesthesia but it takes only about an hour, and most patients go home the next day.

Other Options

In rare situations, a person who is not a good candidate for surgical removal of the cyst may benefit from a permanent drainage tube, or a shunt. Inserting a shunt was once a common technique to relieve blockage of cerebrospinal fluid (CSF). Today, a temporary shunt may be inserted in an emergency, but the procedure has been largely replaced by endoscopic or minimally invasive surgery.

Needle aspiration of a colloid cyst is a simple and quick treatment that involves evacuating the internal part of the cystÑbut this form of therapy has been abandoned due to high recurrence rates.

Here at Weill Cornell, we're doing important research into colloid cysts Ð the tumors are so rare that they are not well understood. Find out more about our research projects, and how you can help.

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