Various tumors originating or secondary to the spinal canal are collectively referred to as intradural tumors, which may also be called spinal cord tumors, and are one of the common causes of spinal cord compression. Tumors that originate in the spinal canal may come from different tissues such as the spinal cord, nerve roots and spinal membranes, and are classified as intramedullary, extramedullary subdural and extradural according to their relationship with the spinal cord and dura mater. Intramedullary tumors commonly include ventricular meningiomas and astrocytomas. Extramedullary subdural tumors are commonly nerve sheath tumors and spinal meningiomas. Extradural tumors are mostly malignant, such as metastases and lymphocytomas, as well as sarcomas, lipomas, hemangiomas, osteomas, chondrosarcomas, nerve sheath tumors, and chordomas, among others. Clinical manifestations The symptoms caused by intradural tumors can be called spinal cord compression, which mainly include the following aspects. 1. Pain: Most of them are caused by extramedullary tumors stimulating nerve roots and spinal membranes, which are often the first and localized manifestations. The pain is spontaneous and often severe; it spreads along the distribution area of nerve roots, and is distributed in transverse strips in the trunk, and radiates from proximal to distal in the extremities; it is paroxysmal at first, and may be aggravated at night or lying down; it may be aggravated by coughing, sneezing or forceful stool; it may be accompanied by spontaneous pain, percussion pain and pressure pain in the spine. 2. Sensory disturbances: such as numbness, ankylosis, burning sensation, banding sensation, etc. Sensory hypersensitivity may also occur, and when the sensory fibers are destroyed, it is manifested as hyperalgesia or absence of sensation. Clinically, the critical surface between the hyperalgesia or absence and the normal sensory area is called the sensory plane, which is one of the important bases for judging the level of spinal cord damage. 3.Motor impairment: The main manifestation is the weakened strength of the limbs below the level of lesion, inaccurate movement and unstable standing, which may or may not be accompanied by muscle atrophy. 4.Dysfunction of urination and defecation: Mostly seen in intramedullary lesions, such as ventricular meningioma, astrocytoma, and cauda equina tumor. Depending on the level of the lesion, it may manifest as defecation difficulty, urinary retention, and fecal difficulty; or it may manifest as urinary and fecal incontinence. Common tumor types 1. extramedullary subdural tumor Nerve sheath tumor is a benign tumor, the incidence of which accounts for the first place of intravertebral tumor. 30-50 years old is the age of prevalence. Most of them originate from the posterior root of spinal nerve, and some of them develop outside the spinal canal through the intervertebral foramen and become dumbbell-shaped. Surgery is the first choice for treatment, and most of them can be completely removed, with very little recurrence and good prognosis. The incidence of spinal meningioma is second only to nerve sheath tumor and is mostly benign. 40-60 years old is the age of prevalence, more women than men. It is more common in the thoracic segment. They are locally adherent to the dura mater. Surgery is the first choice for treatment. Care should be taken to deal with the affected dura mater during surgery, otherwise there is a possibility of recurrence. 2.Intramedullary tumor Ventricular meningioma is a relatively common intramedullary tumor, and most of them are low grade malignant. It is mostly seen in children and young people. The tumor surface has a thin layer of pseudomembrane, which forms a division with normal spinal cord tissue. Surgery is the only effective method, but the timing and indications of surgery are not uniform, usually with moderate neurological dysfunction as the indication. 3. astrocytoma is also a common intramedullary tumor, mostly found in the thoracic spinal cord. mri scan shows local spinal cord thickening with abnormal signals, and some lesions can be enhanced. The tumor is infiltrative growth and lacks clear decomposition with normal tissues, so surgical resection is prone to complications, so careful resection under microscope or biopsy with vertebral plate decompression is required. 4.Epidural tumors are mostly malignant, such as metastases and lymphocytomas, other tumors include sarcoma, lipoma, hemangioma, osteoma, chondrosarcoma, nerve sheath tumor and chordoma. The treatment requires surgery and radiotherapy according to the nature of the pathology. Congenital tumors include epithelioid cysts, dermatomal cysts, teratomas, etc. Both epithelioid cysts and dermatomal cysts originate from the ectopic germ layer that develops into skin in the spinal canal. The walls of epithelioid cysts are translucent, with compound squamous epithelial tissue, and the contents are exfoliated keratinized epithelium, rich in cholesterol crystals. The wall of the cyst is thicker, with more fibrous tissue and dermis at the base of the squamous epithelium, containing skin appendages such as sweat glands, sebaceous glands and hair follicles, and the contents often contain hair. Teratomas are less common and contain tissue originating from all three germinal lobes. Surgical treatment is the only treatment available, and depending on the location and nature of the tumor, the contents of the capsule may be removed, and the wall may be partially or completely excised. In summary, extramedullary subdural tumors are mostly benign, with a long history of disease, and are often seen for pain or decreased strength in the limbs below the level of the lesion, and less often for bowel or urinary dysfunction. Surgical resection is relatively easy, not easy to recur, and the overall prognosis is good with obvious improvement of symptoms after surgery. Intramedullary tumors are usually of low malignancy, with relatively short duration of disease and progressive aggravation after onset. Congenital tumors often adhere closely to the nerve and are not easily removed during surgery, but recurrence is slow and the prognosis is often better.