A hyaloid septal cyst, also known as hyaloid septal dysplasia. Most hyaloid septal cysts are discovered accidentally or incidentally during CT examinations. If they do not cause corresponding symptoms, the CT can be reviewed periodically to see if the cyst continues to increase in size and most do not require treatment. However, some septal cysts, which gradually increase in size and cause headache, memory loss, vomiting, and epilepsy, require surgical treatment. There are 3 main surgical methods as follows: 1. Craniotomy to remove part of the cyst wall, so that the cyst is connected to the ventricle. It is highly traumatic and basically abandoned. 2, cyst-abdominal shunt, the cyst wall is thicker, difficult to puncture, prone to bleeding, and even life-threatening. Postoperative tube is required for life. Once the shunt is blocked, acute intracranial pressure increase can occur. 3.Endoscopic cyst-ventriculostomy, which is less traumatic, safe and effective, has become a mainstream operation.