The sacrum is the lowermost part of the spine. It has a structure that surrounds the hip bone from behind and has a structure that is the continuation of the hip bone. It is located directly above the tailbone. It is one of the most important bones that make up the pelvis.
Sacral tumors are special tumors due to their different anatomic locations, the nerve roots they contain, their relations with pelvic organs and large vessels, and the nuances in their treatment. Some of the sacral tumors may be tumors originating from the sacrum itself, and (metastatic) tumors that spread to the sacrum from other sites are also frequently seen. Benign tumors include giant cell tumors, aneurysmal bone cysts, osteoid osteoma, and nerve sheath tumors. Malignant tumors include chordomas and sarcomas.
In some cases there may be only lower back or leg pain, and in others there may be pain in the tail end. Sometimes there may be numbness or loss of strength in the legs. Urinary, digestive system and fecal problems may occur. Constipation and fullness are sometimes the first symptoms. Sexual dysfunction may occur. Symptoms may present very different clinical conditions depending on the tumor’s location and the mode of spread. In malignant tumors, fever, weight loss and general symptoms of malignant tumors can also encountered. The patient’s complaints, history of the disease and examinations are very important in making a diagnosis.
- Magnetic resonance imaging (MRI) is usually the first requested test. It provides detailed information about the tumor. The relationship of the tumor with pelvic organs is also evaluated.
- Sacrum tomography can provide detailed information about the structures of the spine bones, calcifications in the tumor.
- Angiography can show the blood supply to the tumor tissue and its relationship to the surrounding large vessels.
- X-rays may show deformities and osteoporosis in the sacrum bones.
The most important criterion that determines the treatment in sacral tumors is the type of the tumor. For this, patients usually undergo a biopsy. Treatment is decided depending on the pathology result.
Since radiotherapy or chemotherapy do not have much effect in the treatment of malignant tumors such as chordoma or sarcoma, the primary treatment is the removal of the tumor. The most important point here is the removal of the tumor together with the intact, tumor-free tissues surrounding it. The nerves that control the legs and feet, and the nerves that control the urine and feces, pass through the sacrum bone. In sacral tumors, these nerve structures are usually surrounded by the tumor tissue and cannot be separated. It may be necessary to sever these neural structures while the tumor is being removed.
Benign tumors are usually removed by entering into the tumor and breaking it into pieces. In this way, it may be possible to protect the nerve structures. Lumbopelvic stabilization (fixation of the spine and pelvis with screws) may be necessary after the removal of the entire sacrum bone, a procedure that is also known as total sacrectomy.
Surgical procedures applied on sacral tumors carry a high risk in many ways. Total removal of the tumor is the basis of surgical treatment. However, total sacrectomy is a very nuanced operation due to the characteristics of the site and its relationship with the abdominal and pelvic organs. Therefore, it is important that the operations for sacral tumors are performed by teams experienced in sacrum surgery.
Preoperative angiography and occlusion can increase intraoperative comfort and minimize blood loss. In some cases it is possible to administer effective drugs to the tumor with this method. Although radiotherapy is used to shrink the remaining tumor and prevent recurrence, it is not effective on most of the malignant tumors.
Approximately half of all chordomas are seen in the sacrum. Chordomas are also among the most common tumors that originate from the sacrum. These tumors originate from notochord remnants in the prenatal period, are malignant, and grow slowly. They are more common in middle-aged and elderly individuals. They are twice as common in men compared to women. Chordomas are among the first tumors that should be considered in patients with lower back pain and constipation after forty years of age. Performing a biopsy and confirming the diagnosis before surgical intervention will help with surgical planning. The treatment is to remove the tumor with the surrounding tumor-free and intact tissues without entering the tumor. Operational risks and complications are much lower if an early diagnosis is made.
Tumors such as osteosarcoma, chondrosarcoma, Ewing’s sarcoma can be seen with progressive local pain and, later on, with loss of strength and sense, along with functional disorders. Chondrosarcomas may occur directly in the sacrum or develop as a result of benign tumors such as enchondroma, osteochondroma becoming malignant. These are more common in males at an average age of 45 years, and osteosarcomas are more common in older ages. Only Ewing’s sarcoma can occur in children or young adults and they have a worse prognosis than those seen outside the sacrum. This is due to delayed clinical findings and the fact that they can reach larger sizes. In sarcomas located in the sacrum, it is important to perform PET/CT before surgery and to confirm the diagnosis by biopsy. The treatment is to remove the tumor with the surrounding tumor-free and intact tissues without entering the tumor.
Giant Cell Tumor
Giant cell tumors are the second most common tumors of the sacrum. Although they are typically benign, partial malignancy rates are not very low. It also has the ability to spread to the lungs. They grow by expanding the bones and often will have reached large sizes by the time they are diagnosed. In many patients, a mass may be noticed during rectal examination. The incidence rate is common between the ages of 20-40. They often occur with pain spreading behind the hip. The treatment is surgical. It is important that the mass is completely removed and cleaned as much as possible to avoid recurrence. It is also possible to clean the inside of the tumor by curettage in tumors that cannot be removed completely by circumnavigation. During the operation to remove these tumors, it may be necessary to fix the spine and pelvic bones by placing screws, as in all sacral tumors.