Colloid cyst of the third ventricle

Colloid cyst of the third ventricle has rarely been reported in the ophthalmic literature. The incidence is about one per 1000 in asymptomatic patients and accounts for 0.55 to 2 percent of all intracranial tumors. Although it is an uncommon benign tumor, nearly half of symptomatic patients present with papilledema and hydrocephalus. Consideration of this intracranial tumor should be included in the differential diagnosis of papilledema and apparent unilateral disc edema.

A patient with highly asymmetrical papilledema and vague visual symptomatology involving the right eye was studied. Computer axial tomography (CT) without contrast enhancement revealed a colloid cyst of the third ventricle. Typical symptoms of the condition include headaches, nausea, vomiting, visual obscuration, transient diplopia and weakness of the lower extremities, which are due to acute hydrocephalus caused by increased intracranial pressure from cystic obstruction of the foramen of Monro. Intermittency of symptoms is characteristic of this lesion.

The patient underwent frontal craniotomy with total tumor excision and reopening of the cerebrospinal fluid pathway.

Colloid cyst of the third ventricle discovered incidentally on CT in asymptomatic patients with no evidence of hydrocephalus can be monitored periodically. If symptomatic, neurosurgery is usually indicated since prolonged increased intracranial pressure can lead to mental and physical deterioration as well as sudden death.