The vacuolated butterfly saddle syndrome can be divided into primary and secondary, as follows: a. Primary vacuolated butterfly saddle syndrome: 1. abnormal development of the saddle diaphragm, the mouth of the saddle diaphragm is larger, so the cerebrospinal fluid can accompany the arachnoid membrane to descend and keep falling into the pituitary fossa. 2. endocrine factors, such as when women are pregnant, the pituitary gland will physiologically increase, and after the end of delivery the pituitary volume will shrink, so the space in the saddle area as well as the gap will The pituitary gland will increase in size after childbirth, so the space as well as the gap in the saddle area will be enlarged, which may cause the cerebrospinal fluid to fall and compress the normal pituitary gland. 3. Cerebrospinal fluid and subarachnoid cavity fall into the pituitary fossa together; 2. Secondary vacuolated saddle syndrome: mainly due to tumors in the saddle area or the saddle parietal area, which cause adhesions after doing radiotherapy or surgery, secondary vacuolated saddle syndrome occurs.