RESUMEN
Aim: We describe a case of a 22 year old pregnant female patient who was found to have a small colloid cyst that increased spontaneously, followed by spontaneous significant reduction in size. Presentation of Case: The patient’s colloid cyst was picked up incidentally in late pregnancy at 39 weeks. It showed spontaneous increase in size accompanied by deterioration of symptoms at 31 months post diagnosis and then showed significant spontaneous reduction in size at 38 months post diagnosis. Discussion and Conclusion: Spontaneous reduction of a colloid cyst of third ventricle is a very rarely described phenomenon. To our knowledge this is one of only 3 cases of spontaneous regression of an III ventricular colloid cyst. It may be reasonable to follow up cases, where there is a documented history of increase.