Endoscopic Resection of Colloid Cyst of the 3rd Ventricle

Endoscopic Resection of Colloid Cyst of the 3rd Ventricle

This 50y female had been followed in our practice since 2009, when she presented with an incidental finding of a small colloid cyst of the 3rd ventricle. At the time it was not causing any hydrocephalus and a watch and wait policy was adopted. Here is an axial T2 MRI showing the cyst (small dark lesion at foramen of Monro).

Over the years she had remained stable but in recent months started to have more frequent headaches, and a follow up MRI demonstrated slight growth of the cyst and early obstructive hydrocephalus.

Surgical intervention was recommended. This was performed endoscopically with stereotactic guidance, and complete removal of the cyst was achieved. This was performed through a 3cm right frontal incision and a single burr hole, at the Wesley Hospital, Brisbane.

The postop CTs show the cyst has been removed, and just a small amount of blood at the site of the cyst resection.

The procedure was uneventful, and the patient was discharged from hospital 3 days after surgery.

Colloid cysts are uncommon but well known lesions. They can be detected incidentally, such as in this case, and in those situations, cysts that are less than 10mm in diameter and not causing hydrocephalus are usually monitored with MRI scans. Colloid cysts may also present with hydrocephalus, due to obstruction of the foramen of Monro, causing symptoms of raised intracranial pressure (headaches and drowsiness) and in extreme cases this can be an acute situation over a matter of days. Rarely if ever do colloid cysts cause sudden onset of headaches which is positional (a textbook but not real life description).

Treatment is indicated if cysts are shown to increase in size and/or cause ventricular dilatation.

If colloid cysts are causing symptoms, urgent surgical treatment is needed. It is not advisable to sit on patients in this situation, even for 1 night.

Surgical options range from shunting, stereotactic aspiration, open resection (trans-cortical or trans-callosal), or endoscopic resection.

It is clear, in most situations, that endoscopic resection is the treatment of choice. It is associated with less morbidity (less brain manipulation is required compared to open resection) and a quicker recovery. However, it does require a highly skilled and experienced team and equipment, such as available at the Wesley Hospital with Brizbrain and Spine.

By Professor David Walker BMedSc, MBBS, PhD, FRACS