Large glial cyst of the pineal gland: a possible growth mechanism. Case report.

The authors report on a patient who presented with a large symptomatic glial cyst of the pineal gland communicating with the third ventricle. The hole between the ventricle and the cyst, suspected on magnetic resonance images, was found at surgery. The to-and-fro flow mechanism is considered to be involved in the pathogenesis of growth in this unusual large glial cyst of the pineal gland, although this mechanism cannot be applied universally.