How does spinal canal tumor form?

summary

The spinal canal is a pipe formed by the intervertebral foramen on the spine. There are many layers of structures in the spinal canal. The innermost spinal cord and the outermost dura mater are the tumors originated from the spinal cord, which are called spinal cord tumors (also known as intramedullary tumors). The tumors originated from the spinal cord and dura mater are called extramedullary subdural tumors. Among them, the most common extramedullary subdural tumors are schwannoma and meningioma, and the more common intramedullary tumors are ependymoma, astrocytoma and angioreticuloma. 90% of these tumors are benign. So how does spinal canal tumor form? Come and study with me.

How does spinal canal tumor form?

First of all, it is related to the location of tumor compression and the nature of nerve tissue structure: the tolerance of various spinal cord nerve tissues to pressure is different: for example, the tumor first stimulates and then destroys the nerve root; The tolerance of gray matter to tumor compression was greater than that of white matter; In white matter, pyramidal tract and nerve fibers conducting proprioception and touch were thicker (diameter 5 μ m～21 μ m) The diameter of pain fiber was less than 2 μ m) After compression, the tolerance of fine fibers was greater than that of coarse fibers, and the recovery was faster after the compression was relieved. Generally speaking, at the beginning of compression, the nerve root is pulled, the spinal cord is displaced, then compressed and deformed, and finally the spinal cord degenerates, which gradually leads to neurological dysfunction of the tissue.

Secondly, the influence of tumor on blood circulation of spinal cord: venous dilatation, blood stasis and edema after venous compression; After the compression of the artery, the blood supply of the innervated area is insufficient, hypoxia and nutritional disorders, resulting in the degeneration and softening of the spinal cord, and finally the necrosis of the spinal cord. In terms of tolerance to ischemia, gray matter was larger than white matter, and fine nerve fibers were larger than coarse nerve fibers. It was reported that the dorsal surface of the spinal cord was blue, the nutrient artery was enlarged, and the drainage vein was significantly missing, but a small number of small nutrient arteries could be seen under the microscope.

Finally: the hardness of the tumor is closely related to the degree of damage to the spinal cord: soft tumors, especially those with slow growth, make the spinal cord have enough time to adjust its blood circulation, develop slowly, have mild symptoms, and recover quickly and perfectly after operation. Hard tumors, even small in size, are easy to be embedded in the spinal cord. Any spinal activity can cause spinal cord contusion and gliosis, and most of them are not ideal for postoperative recovery.

matters needing attention

It is related to the growth pattern and growth rate of tumor: some intramedullary tumors are mainly dilated growth, some are mainly invasive growth. The latter caused more damage to the spinal cord. If the tumor grows slowly, even if the spinal cord is obviously compressed, the symptoms may be mild due to the compensatory ability of the spinal cord; On the contrary, fast-growing tumors, especially malignant tumors, are easy to cause symptoms of acute and complete spinal cord transection damage. Emergency surgery is needed to relieve spinal cord compression, even if the delay of 1-2 hours, it will often cause serious consequences.