Temporal bone bulge

A temporal bone bulge is a symptom of an arachnoid cyst. Arachnoid cysts are a type of benign brain cyst. There are arachnoid cystic wall and cerebrospinal fluid-like cystic fluid. The cyst is located on the surface of the brain and is closely related to the subarachnoid space, but does not invade the brain. Most of them are single, and a few are multiple, often located in the cleft of the brain and cerebellum. Larger people can compress brain tissue and skull at the same time, which can produce neurological symptoms and skull changes.