Currently, in clinical practice, patients with sacral cysts protruding into the pelvis often present first to gynecology or anorectology because the clinical presentation is often accompanied by pelvic symptoms, paracentesis and intestinal symptoms, which can easily lead to misdiagnosis. Some patients are occasionally detected by routine gynecologic physical examination ultrasonography, and these patients also tend to be seen first in gynecology. Among them, there are many cases of gynecological surgery for adnexal cysts. Therefore, for these patients, it is recommended to improve multiplanar MRI scans of the sacrococcygeal spine, especially coronal MRI reconstruction or CT thin-section coronal reconstruction, which can be quite helpful in determining the origin of the cyst, the number of cysts and the location of the nerve root outlet. In principle, patients with sacral cysts protruding into the pelvic cavity and with corresponding clinical symptoms should be actively treated by surgery as early as possible. For patients with no obvious symptoms, surgery should also be recommended. Cysts protruding into the pelvic cavity tend to progress faster due to bone defects, and the larger the cyst is, the more difficult it is to treat clinically. These cysts originate from the sacral nerve roots and the cyst leak is located in the sacral sheath in the sacral canal. Therefore, the most important thing at this time is to seal the leak of the cyst in order to finally achieve the purpose of radical treatment. The following cases of sacral cysts protruding into the pelvic cavity were treated in our center, and the patients showed significant improvement in their symptoms after surgery, and the MRI review was also very satisfactory. Frequently asked questions: A. How to differentiate adnexal cysts or pelvic cysts from sacral cysts. A: It is recommended to consult the lumbosacral nerve center of neurosurgery. Such patients are recommended to perfect a multiplanar MRI scan of the sacrococcygeal spine. Especially, the reconstruction of MRI in coronal position can be quite helpful in determining the origin of cyst, the number of cysts and the location of nerve root exit. Third, can minimally invasive laparoscopic surgery be performed for sacral cysts that protrude into the abdominal cavity? A: No. Such cysts protruding into the abdominal and pelvic cavities have their roots from the nerve sheaths in the sacral canal, and surgery simply for the cysts is often ineffective, with early recurrence. It is more likely to cause intraoperative nerve root injury and persistent postoperative cerebrospinal fluid leakage with unimaginable consequences. Therefore, we recommend sacral canal cyst blocking surgery in order to solve the problem at its root.