Anterior sacral tumors are a rare but noteworthy problem. Anterior sacral tumors are tumors that occur in the sacral and rectal space, also known as retrorectal tumors. I. Incidence: The disease is more common in female patients, and most of them are benign. Malignant tumors are more common in children than in adults, and solid tumors are more likely to be malignant compared to cystic tumors. The incidence rate in general hospitals is about 0.0025-0.014%, and the number of patients diagnosed with posterior rectal tumor in large hospitals is about 1-6 per year. Classification: Pre-sacral tumors are divided into four categories: congenital, neurogenic, bony and mixed, each of which can be divided into multiple lesions. Congenital lesions account for 2/3 of pre-sacral tumors, of which 2/3 are congenital cysts and 1/3 are solid tumors. (i) Dermatomal cysts and epidermoid cysts: Dermatomal cysts and epidermoid cysts are benign lesions originating from the ectoderm. These lesions are called epidermoid cysts if the cyst wall is lined with squamous epithelial cells and dermal appendages if the cyst wall is lined with squamous epithelial cells and skin appendages. Sometimes the cysts are attached to the skin and form a dimple sign above the posterior anus. Infection occurs in about 30% of cysts. Once infected, cysts are easily misdiagnosed as perianal abscesses, fistulas, and fistulas. Recurrence of cysts after surgical treatment should be considered as possible congenital cysts. (ii) Repetitive hindgut cysts: Isolated hindgut tissue during embryonic development can lead to thin-walled multihoused cysts lined with columnar epithelium. Hindgut cysts can also present as single-compartment, called posterior rectal cystic malformations. Rectal duplication cysts can also contain various components of the intestinal wall. These cysts are mostly benign, but can also present with malignant changes. (iii) Anterior meningocele: Anterior meningocele of the cerebrospinal and seminal spine is caused by herniation of the dural sac from a defect anterior to the sacrum. A unilateral sacral defect may show a typical scimitar sign on radiographs. Patients often have no specific symptoms, but may have headache. Headaches tend to come on during changes in position, changes in intra-abdominal pressure or during defecation. Puncture drainage is contraindicated because it can lead to meningitis. (iv) Chordoma: Chordoma originates from the spinal cord and is the most common malignant tumor of the presacral space. Chordoma is often associated with pain and is more common in men than in women. Chordomas can occur anywhere in the spinal cord, but are most common in the sacrococcygeal region. These tumors are slow growing but aggressive and can lead to typical bone destruction. Radical resection is the most effective treatment, but the local recurrence rate is high, with a 10-year survival rate of only 9% to 35%. (v) Teratoma: Teratomas are true tumors containing tissue of polyembryonic origin and can be either cystic or solid, but are usually mixed cystic and solid masses. As with dermatomal cysts, they are more common in women. Many teratomas contain embryonic cells with malignant potential, and about 10% of teratomas can progress to cancer. Teratomas are more common in children than in adults, and adult teratomas are more likely to be malignant. Teratomas usually contain a variety of tissue components, including respiratory, neurological, and digestive structures. These lesions are often closely associated with the tailbone, and surgery requires that the tumor and tailbone be removed in one piece. (vi) Residual adrenal tumors: Residual presacral adrenal tumors are very rare and are often classified as miscellaneous although they have the nature of congenital tumors. They are usually treated as ectopic adrenal tumors. (vii) Neurogenic tumors: They often originate from peripheral nerves and account for about 10% of presacral tumors, including neurofibroma, neurofibrosarcoma, nerve sheath tumor, ventricular meningioma, and ganglioneuroblastoma. Among them, nerve sheath tumors are the most common, and larger nerve sheath tumors can become cystic. (H) Bone tumors: Tumors of bone origin account for about 10% of presacral tumors, including bone cysts, osteogenic sarcoma, Ewing’s tumor, chondromyxosarcoma, and giant cell tumor of bone. giant cell tumor). Although benign tumors of presacral bone origin can be resected radically, local recurrence may be the biggest problem. Malignant tumors of bone origin tend to develop rapidly and have a poor prognosis. (ix) Inflammatory lesions: Inflammatory lesions may be solid or cystic, often due to the spread of infection in the perirectal space or retroperitoneal space. Pelvic and perineal infections can also spread to the presacral space. Crohn’s disease and rectal diverticulitis can also present as presacral inflammatory lesions. In addition, some rare inflammatory diseases, such as tuberculosis and granulomatous diseases, can also present in the presacral space. (J) Other tumors: The presacral space also includes a variety of other benign and malignant tumors, including metastatic disease, lymphangioma, leiomyoma, fibrosarcoma, endothelioma, and sclerofibroma. The treatment and prognosis depend on the nature of the pathology. Anatomy: The presacral space is a potential gap between the sacrum and the rectum, with the upper border of the peritoneal reentry, the intrinsic fascia of the rectum in front of the space, the presacral fascia behind, the ureter and iliac vessels laterally, the lateral ligaments anteriorly and laterally, and the rectosacral fascia below, leading above to the retroperitoneal space and below to the pelvic-rectal space. Because the anterior sacral hiatus contains totipotent cells derived from different germ layers, tumors of different nature can occur in the hiatus. In recent years, with the development of CT and MRI imaging, it has provided ideal anatomical basis for the diagnosis and surgical treatment of presacral tumors. Clinical manifestations: presacral tumors start insidiously, develop slowly, and most of them have no obvious symptoms; when symptoms appear, it is often more difficult to treat because the tumor is already large. Pre-sacral tumor usually lacks typical clinical symptoms. Possible symptoms are anal swelling, difficult defecation or overflowing fecal incontinence, lumbosacral distension or lower limb pain, recurrent anal fistula or abscess; anterior cerebrospinal bulge may have postural headache; huge tumor may lead to intestinal obstruction and also obstruction of the birth canal, resulting in life-threatening obstructed labor. Most patients have no obvious symptoms or lack of specific symptoms are often not easily detected, often because the tumor is found by CT or MRI imaging. Most tumors can be detected by rectal examination. Careful rectal palpation can provide some information for the diagnosis of presacral tumors, and most patients are able to detect extra-mural masses in the posterior or lateral aspect of the rectum. Because MRI can provide multidimensional imaging structures and better soft tissue contrast, it is superior to CT in the imaging diagnosis of presacral tumors; MRI can effectively assess the location, size, malignant potential, and relationship with surrounding tissues of presacral tumors and provide accurate surgical strategies. V. Puncture biopsy: For resectable tumors, puncture biopsy is not recommended. For cystic tumors, puncture and aspiration may lead to infection; for cerebrospinal bulge puncture may lead to meningitis; for malignant tumors puncture may lead to tumor spread and needle tract implantation metastasis. Puncture biopsy is primarily used for non-surgically resectable lesions and can guide non-surgical treatment. Puncture biopsy can also be used in cases of combined severe cardiovascular disease that cannot tolerate pelvic surgery. The best management strategy for presacral tumor is surgical resection, and the surgical route directly affects the exposure of the tumor and whether it can be completely resected. It is generally believed that tumors above the sacral 3 plane should be resected through the abdomen, while those located below the sacral 4 plane should be resected through the sacrococcygeal plane, and a combined abdominal-sacral resection can be used in between. In fact, transabdominal surgery is the best choice regardless of tumor location; especially when performed by an experienced gastrointestinal surgeon, there are few complications. The transabdominal route allows for the removal of the majority of presacral tumors, using sharp separation when possible and avoiding excessive blunt separation. Laparoscopic surgery is superior to open surgery, especially in male patients. If the tumor invades the rectum, en block resection should be performed with the tumor. In case of sacrococcygeal invasion, caudal and or sacral resection is required. For these complex cases, it often requires the collaboration of gastrointestinal surgery, neurosurgery, orthopedics and plastic surgery to ensure the success of the surgery. The prognosis after surgical resection of presacral tumors depends on the pathological nature of the tumor and the adequacy of the surgical resection. The surgical outcome of benign tumors is often satisfactory and the recurrence rate is low. Recurrent tumors can be radically resected again. Teratomas tend to accumulate in the tailbone, and caudal resection for teratomas that accumulate in the tailbone can reduce the risk of tumor recurrence. The prognosis after resection of malignant tumors is highly variable, which is related to the biological characteristics of the tumor. Local recurrence of chordoma is common, with 5-year survival rates ranging from 43% to 75% and 10-year survival rates ranging from 9% to 35%. The prognosis of other malignant tumors tends to be poorer. Although there is a lack of specific clinical manifestations and signs, rectal examination can reveal almost all of the presacral tumors. Pelvic CT or MRI examination can assess the exact presacral tumor location, size, preliminary determination of tumor benignity and malignancy, relationship with surrounding tissues and provide the correct surgical strategy. Transabdominal surgery has few complications and is the best surgical route for the treatment of presacral tumors.