1. What is an intravertebral tumor? Intraspinal tumors are also known clinically as crestal medullary tumors. It refers to tumors that occur in the crestal medulla itself and in the spinal canal adjacent to the crestal medulla. 2. What are the types of intradural tumors? According to the relationship between the tumor and the crestal medulla and the dura mater, there are three types of tumors from the inside out: intramedullary tumors, extramedullary subdural tumors, and extradural tumors. Extramedullary subdural tumors are the most common, accounting for about 40-60% of all cristae medullaris tumors, and commonly include cristae tumors, nerve sheath tumors, vascular malformations, arachnoid cysts, lipomas, etc.; followed by intramedullary tumors, which commonly include astrocytomas, ventricular meningiomas, hemangioblastomas, cysts, congenital tumors, etc. The types of extradural tumors are variable, including angiomyolipoma, metastases, etc. Malignant extradural tumors are more common. According to the distribution area of tumors in the crest, they can be classified from top to bottom: craniocervical junction area, cervical spine (high cervical and lower cervical spine), thoracic spine, lumbar spine, and sacral spine intravertebral canal tumors. According to the location of tumors in relation to the crestal medulla, they can be divided into: dorsal crestal medulla, dorsolateral crestal medulla, ventral crestal medulla, and ventral crestal medulla tumors. The surgical difficulty of tumors in different locations varies greatly. Generally speaking, high cervical, crestal ventral, and crestal intramedullary tumors are relatively more difficult to operate, and require higher skills, experience, and specialized neurosurgical equipment of neurosurgeons. 3. Are intramedullary tumors benign or malignant? Most of them are benign, such as nerve sheath tumor, cremasteroma, hemangioblastoma, etc. Some of them are malignant, such as astrocytoma, metastasis, lymphoma, etc. How are intramedullary tumors formed? Who are prone to get it? There are many types of intravertebral canal tumors and most of them do not have a clear cause of development, but current research has found that they may be slightly related to genetic factors, external forces and stress factors, and changes in the local chemical or biological environment of the spinal canal. In terms of morbidity characteristics, the peak age of onset is 40-70 years, and both men and women can develop the disease. A few intravertebral tumors, such as intravertebral angioblastoma in “Hippel-Lindau syndrome” and intravertebral neurofibroma in neurofibromatosis, are usually associated with genetic variants. However, most other types of intradural tumors do not have a clear cause. What are the symptoms of intradural tumors? The most common symptoms of intravertebral tumor are pain, numbness, weakness or difficulty in moving the limbs, difficulty in urinating and defecating, and sexual dysfunction of the trunk or limbs. If the tumor is located in the cervical spine, it mainly manifests as pain, numbness and weakness in the occipital neck and upper limbs. If the tumor is located in the thoracic spine, it mainly manifests as pain and numbness in the thoracic back and sensory sensitivity. If the tumor is located in lumbosacral vertebra, it mainly manifests as pain and numbness in the waist, hip and lower limbs, difficulty in urination and defecation, and decrease in sexual function. 6. What symptoms should we suspect intravertebral tumor? The main danger of intravertebral tumor, regardless of the type, lies in the persistent and progressive compression of the crestal medulla and crestal nerve, resulting in the dysfunction of the crestal medulla and crestal nerve. Therefore, if there is persistent and progressive aggravation of pain and numbness in the crestal area, pain and numbness in the limbs, weakness in the upper limbs or unstable walking in the lower limbs, difficulty in urination and defecation, and decreased sexual function, the possibility of intravertebral canal tumor should be considered. Many patients are often misdiagnosed as cervical spondylosis or lumbar disc herniation and delay treatment or delay treatment. 7. What tests should be done if I have intravertebral tumor? Crestal magnetic resonance imaging (MRI) is the best and most important test to diagnose intravertebral tumor. The location, size, and relationship of the tumor to adjacent structures are clearly shown by MRI, the nature of the tumor is initially determined by MRI, and the doctor’s treatment strategy is based on MRI. In addition, the doctor will arrange some other auxiliary examinations after admission, such as limb evoked potential examination and crestal X-ray, etc. 8. How should I treat intravertebral canal tumors? (1) Benign tumors in the spinal canal: microsurgical resection is the most fundamental treatment. Benign tumors such as intraspinal nerve sheath tumors, cremasteric tumors, and hemangioblastomas can be cured at a high rate through surgery. Today, with highly developed techniques and equipment such as neuro-microscopy, neuro-navigation technology, intraoperative real-time electrophysiological monitoring technology, neuro-endoscopic technology, and intraoperative ultrasound, most of these surgeries can result in radical resection while achieving optimal neurological function protection. (2) Intravertebral malignant tumor: A comprehensive treatment based on microsurgical resection, supplemented by radiotherapy and chemotherapy treatment. Under the premise of protecting neurological function, the tumor is removed to the maximum extent to achieve two purposes: first, complete removal of the tumor or most of the tumor is removed to relieve the compression of the crestal medulla by the tumor, thus relieving the symptoms. Secondly, it clarifies the pathological type and molecular typing, and provides a pathological basis for adjuvant radiotherapy treatment. 9. What is the surgical approach for intravertebral tumor? Microsurgical resection The surgery is performed under a high-definition microscope in neurosurgery, with several times magnified field of view, and the crestal medulla and its surface vascular structures are clearly visible, while the crestal medulla is incised longitudinally and the tumor is carefully separated and removed with microscopic instruments under the protection of real-time intraoperative electrophysiological monitoring. This is a very delicate operation, and a slight improper separation may result in serious consequences, so it requires the patience and careful operation of an experienced neurosurgeon. 10. Is the surgical result of intravertebral tumor good? The factors affecting the surgical outcome are comprehensive, including the relationship between the tumor and the cremaster, the patient’s neurological function status before surgery, the level and experience of the surgeon, and proper postoperative rehabilitation, etc. Therefore, a comprehensive, individualized and precise surgical plan needs to be formulated. With the continuous development of microscopic technology, intraoperative electrophysiological technology, intraoperative navigation technology, intraoperative visualization and other technologies, the cure rate of intravertebral canal tumors is getting higher and higher. 11. What are the risks of intravertebral canal tumor surgery? The most common symptoms and complications after surgery include: limb pain, numbness, limb movement disorder, infection, etc. Limb pain and numbness are relatively common postoperative symptoms, but most of them gradually resolve within six months after surgery. 12. What is the difference between intradural tumor and crestal tumor? Intradural tumor is a tumor involving crestal medulla and crestal nerve, and together with cranial tumor, it constitutes a central nervous system tumor, which undoubtedly belongs to neurosurgical disease. Therefore, this kind of tumor surgery requires neurosurgeons to perform, and requires advanced equipment such as special high-definition microscope, microscopic instruments for cremaster, intraoperative neurophysiological monitoring, intraoperative navigation, etc. Of course, more importantly, a team of neurosurgeons with skillful microsurgery techniques and rich experience in cremaster surgery is required. Crestal tumor is a tumor growing on top of the crestal bone, which is a part of bone tumor, and this kind of disease belongs to crestal surgery, which can belong to neurosurgery and orthopedic branch in foreign countries. In China, most of these diseases are now classified as orthopedics, however, more and more neurosurgical centers are involved in the field of crestal tumors. This is due to the fact that more and more neurosurgeons are using internal fixation techniques, which, together with the unique microscopic techniques, offer an inherent advantage in the treatment of these tumors.