(A) Diagnostic basis
1.Clinical manifestations
It mostly appears as pain, neurological impairment, mass, pathological fracture, etc. It may also be found by occasional physical examination. Malignant and rapidly developing cases may show systemic symptoms, but they are relatively rare. For example, multiple myeloma may be accompanied by fever, weakness and wasting. Most patients with metastatic tumors have symptoms of the primary lesion, but some patients have a small or even no primary lesion to find.
Ask about family history, past history, comorbidities, etc.
2. Imaging examination
The commonly used diagnostic imaging methods include X-ray, CT, MRI, bone scan, PET/PET-CT, etc. Imaging examinations can provide accurate local anatomical features and other information to determine distant metastasis and local recurrence after treatment.
(1) X-ray: Routine examination, but with low sensitivity. It is generally considered that vertebral destruction of more than 30% to 50% is required to detect bone destruction on X-ray. It is one of the features of malignant tumor when the vertebral arch is involved, which is shown as owl blink sign on X-ray. there can be three types of manifestations on X-ray: osteolytic, osteogenic and mixed type, the former being the most frequent. The osteogenic form is more easily detected on radiographs, which can easily detect compression and burst fractures and spinal deformities in the weight-bearing state. dynamic flexion-extension radiographs can also be used to determine spinal instability and can be a good complement to other imaging studies at follow-up. The presence of new osteosclerosis during treatment is often a sign of a good response to treatment.
（The main advantage of CT is that it can clarify microscopic damage to the bone cortex and trabeculae, and can accurately show osteolytic or osteogenic lesions in the vertebral body to assess the occurrence of pathological fractures and instability. It can also provide more detailed information for surgical planning through reconstruction. The disadvantage is that the radiation dose is higher than that of X-rays and is susceptible to interference from metallic endophytes.
(3) MRI: MRI has high sensitivity and specificity and can detect lesions larger than 3 mm. When the tumor invades the spinal canal, MRI can accurately reflect the segment and severity of spinal cord and nerve root compression.
(4) Bone scan: The advantage is that the whole bone can be scanned and imaged on a single image with high sensitivity. However, the specificity of bone scan is not high because it reflects the activity of osteoblasts rather than the proliferation of tumor cells. When the lesion only destroys bone with little or no osteogenesis, the bone scan shows negative results, as seen in multiple myeloma, small cell lung cancer, and renal cancer metastases. Pathological fractures may also show positive results.
(5) PET-CT: Compared with conventional PET, PET-CT improves the accuracy of lesion localization, facilitates better interpretation of PET images, and reduces false positives and false negatives of PET. “(i.e. localization, qualitative, periodic and quantitative). However, the disadvantage is the high cost.
3. Laboratory tests
Generally within the normal range. A few patients may have increased blood sedimentation, anemia and increased alkaline phosphatase. Tumor markers may be abnormal in metastases, such as CEA (carcinoembryonic antigen), AFP (alpha-fetoprotein), CA199, CA125, PSA (prostate-specific antigen), etc.
4. Pathological biopsy
There are incisional biopsy and puncture biopsy. The former has a lot of damage, bleeding and small lesions are not easy to take accurately. Advances in imaging technology and puncture needle design can make biopsies safer and more accurate. The use of excisional biopsy has decreased significantly and is only used when puncture biopsy fails.
CT-guided percutaneous puncture biopsy is now recognized as the best method to obtain a preoperative pathologic diagnosis of spinal lesions, with a positive biopsy rate of 94.60% and a postoperative pathologic confirmation biopsy compliance rate of 95.62%. If the spinal tumor contains a paravertebral soft tissue mass, ultrasound-guided puncture biopsy is also feasible.
(B) Diagnosis
With the advancement of imaging, the diagnosis of spinal tumor is also progressing, but it still follows the principle of clinical-imaging-pathological triad. Not only accurate qualitative diagnosis of spinal tumor is needed, but also clear localization diagnosis, including the number of spinal involvement, metastasis of important organs, spinal stability, whether and to what extent the spinal cord is compressed, and the extent of local soft tissue invasion.
(3) Surgical staging of spinal tumor
Surgical staging of spinal tumors: In 1980, Enneking proposed a surgical staging of spinal tumors (see Appendix A for Enneking’s staging), which is widely used for bone and soft tissue tumors of the extremities, but difficult to use for spinal tumors. Spine tumor surgeons are increasingly faced with many difficult cases due to previous intratumoral scraping or excisional biopsies. 1997 Boriani et al. in Italy proposed the WBB surgical staging of spine tumors in the thoracolumbar spine (see Appendix C for WBB staging of thoracolumbar tumors and Appendix E for WBB staging of cervical tumors). In contrast, Tomita et al. in Japan divided thoracolumbar spine tumors into seven subtypes (see Appendix D for Tomita staging of thoracolumbar spine tumors). These efforts provide a reference standard for planning surgical procedures and approaches and comparing surgical outcomes. In recent years, the findings of several medical centers have confirmed the effectiveness of WBB staging and whole tumor resection for the treatment of primary malignant tumors of the spine.
(IV) Differential diagnosis
1, spinal tuberculosis: there are mostly chronic toxic symptoms such as low fever and night sweats, and the lesions mostly erode the intervertebral discs and the corresponding vertebral body margins, and paravertebral cold-shaped abscesses help in the differential diagnosis.
2, degenerative spinal lesions: intervertebral discs, ligaments protrude into the spinal canal causing spinal cord and nerve compression. Imaging signs of spinal degeneration are almost always present after middle age, and the differential diagnosis of spinal cord tumors depends on careful neurological evaluation, supplemented by imaging.
3, septic inflammatory disease of the spine: before the onset, the patient mostly has skin boils or other septic foci, high temperature, obvious symptoms of toxicity, pain in the affected area, limited movement, local soft tissue swelling and pressure pain. x-ray of the vertebral body can be seen bone destruction, narrowing of the intervertebral space, often with dead bone formation, mostly without abscess formation, the diagnosis should be confirmed by bacterial and histological examination.
4.Other: Through medical history, clinical manifestation and auxiliary examination, it can be differentiated from spinal cord tumor, ankylosing spondylitis and other occupational and inflammatory lesions.
I. Specification of spinal tumor treatment
(1) Principles of surgical treatment for spinal tumors
First of all, we should make a clear diagnosis and preliminary staging. Although surgery is still the main treatment modality for primary tumors of the spine, the treatment plan should be decided preoperatively by multidisciplinary collaboration under the leadership of spine tumor surgery: interventional department should perform embolization or aortic balloon to reduce intraoperative bleeding; vascular surgery should assist in freeing the vessels to reveal the tumor, or even vascular bypass (aorta, vertebral artery, etc.); anesthesia department should control pressure reduction, reduce intraoperative bleeding, and monitor neurophysiology; after tumor removal, plastic surgery should assist in metastasis. After removal of tumor, the Department of Formation assists in transferring flaps or myocutaneous flaps to reduce the cavity and close the incision; the intensive care unit strengthens postoperative management and support; the Department of Medical Oncology decides the plan and timing of drug treatment; the Department of Radiotherapy decides the mode and timing of radiotherapy.
Enneking staging can be a good guide for the treatment of extremity tumors. Among the primary malignant bone tumors of the extremities, osteosarcoma, chondrosarcoma, and Ewing sarcoma are common, mostly highly malignant, with many early metastases; while among the spinal tumors, chordoma and giant cell tumor of bone are common, mostly low-grade malignant or junctional, easy to local recurrence, and metastases are relatively rare. (See Appendix B for treatment principles of Enneking’s oncologic staging.)
Most spinal tumors are ineffective to chemotherapy. Surgical treatment is mostly transmural surgery, but also repeated tumor reduction surgery with preservation of neurological function. Surgical margins free of tumor are often more important than preserving neurological function and maintaining spinal stability.
1, When dural sac and spinal cord spinal tumors invade the spinal canal, marginal resection (preservation of the dural sac) or extensive resection (removal of the affected dural sac) is performed.
In contrast, the nerve root function of C1-4 and T2-12 is less important and can be cut. For example, in TES surgery, the corresponding pair of thoracic nerve roots of the lesioned segment should be routinely cut, while C5-T1 and L3-S2 nerve roots should be cut with caution because of the obvious neurological impairment. If extensive resection is proposed, it is also necessary to cut them if necessary.