Intramedullary tumor

Introduction to intramedullary tumors Intramedullary spinal cord tumors are not uncommon in spinal cord tumors. Intramedullary tumors are basically divided into two categories: one is a primary intramedullary tumor; the other is a secondary intramedullary tumor. The latter is less, often intracranial tumors to disseminated tumors into the spinal canal, such as medulloblastoma, germ cell tumor, less astrocytoma, glioblastoma multiforme or fourth ventricle Tumor and the like. It is very rare for gliomas that originate in the spinal cord to spread intracranially. Although the composition of the spinal cord and brain cells is the same, the gliomas in the spinal cord are much less numerous than the gliomas in the brain. Tumors originating in the spinal cord can grow in any segment of the spinal cord, mainly in the neck and chest. The intramedullary ependymoma is the most common in the cervical segment, and the astrocytoma neck is roughly the same as the thoracic segment. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: edema, cerebrospinal fluid leakage

Intramedullary tumor etiology

Causes

Intramedullary tumors are common in ependymoma, followed by astrocytoma, but in the case of intramedullary tumors, some ependymoma occur in the cone-shaped conic region. When discussing intramedullary tumors, tumors in the cauda equina are generally Excluding such cases, other tumors include vascular reticuloma, cavernous hemangioma, lipoma, metastatic carcinoma and tuberculosis, rare cystic worms, melanoma, etc. The most common, accounting for more than 80%, spinal cord intramedullary tumors are closely related to syringomyelia, but the underlying cause is still unclear. Vascular reticuloma accounts for 8.8%. In cases of ependymoma, the cervical segment is significantly higher than the thoracic segment. The incidence of cervical intramedullary ependymoma is twice that of the thoracic segment, while the incidence of astrocytoma and cervical and thoracic intramedullary tumors accounts for almost 50%.

Pathogenesis

1. Astrocytoma: About 3% of central nervous system astrocytomas originate in the spinal cord. These tumors can occur at any age, but they seem to be in the 30-year-old age group. Intramedullary tumors are also common in children. 60% of tumors occur in the spinal cord at the junction of the cervical vertebrae and the neck and thoracic, and can occur in the thoracic vertebrae, lumbosacral vertebrae or conus in the spinal cord, but the terminal filaments are rare. Spinal astrocytoma can be characterized by histology, biological behavior, and natural history. These tumors include low-grade fibrosis and capillary astrocytoma, malignant astrocytoma, and glioblastoma. Ganglion glioblastoma, occasionally oligodendroglioma, about 90% of children with astrocytoma are benign, including fiber type I and II, about 1/3 of childish hair cell stars Patients with axonoma and ganglion glioblastoma are not associated with a history of pain, approximately 10% of children with glioma, malignant astrocytoma or glioblastoma, and fibrous astrocytoma is predominantly adult , immature hair cell astrocytoma and ganglion glioma are rare, usually more common in adolescence, adult hair cell astrocytoma, usually rich in hair cell specific structure, it is not clear whether it is rich Hair cell characteristics predict a good prognosis for the lesion.

2. Ependymoma: Ependymoma is the most common intramedullary tumor in adults. It can occur in any age group, but it is most common in middle-aged people. The ratio of male to female is almost equal. There are a series of histological subtypes. Cellular ependymoma is the most common type, but epithelial, fibrous, subependymal, mucoid or mixed type is also common, most of which are histologically benign, although no cystic capsule Formation, these glial cell-derived tumors usually have better borders and rarely infiltrate adjacent spinal cord tissue.

3. Vascular reticuloma: vascular reticuloma accounts for 3% to 8% of intramedullary spinal cord tumors, 15% to 25% of patients with von Hippel-Lindau syndrome, an autosomal abnormal defect disorder, these Tumors can occur at any age, but adolescents are rare. Vascular reticuloma is an angiogenic benign tumor with clear margins, intact capsule, and adhesion to the soft membrane. The tumor is usually located on the dorsal or dorsal side.

4. Other tumors: Embryogenic tumors and cysts rarely occur in the intramedullary space. Lipoma is the most common abnormal tumor of embryonic development, accounting for about 1% of intramedullary tumors. These are not true tumors, originating from embryos. Mesoderm tissue, which can be increased by fat metabolism deposition, increases in the young adult and produces symptoms, these lesions are considered intramedullary lesions, because they are usually located in the subdural area, metastatic tumors account for about intramedullary tumors 2%, lung cancer and breast cancer are the most common source of primary tumors, melanoma, melanoma, fibrosarcoma, myxoma is also the most common intramedullary metastases, vascular malformations, especially cavernous hemangioma is also considered It is an intramedullary tumor.

Intramedullary tumor prevention

There are no special preventive measures for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Intramedullary tumor complications Complications, edema, cerebrospinal fluid leakage

Intramedullary tumors, such as surgery, may have the following complications:

Epidural hematoma

Paravertebral muscles, vertebrae and dural venous plexus are not completely hemostasis. Hematoma can form after operation, resulting in aggravation of limb paralysis. It occurs within 72 hours after surgery. Hematoma can occur even in the case of drainage tube. A phenomenon should be actively explored to remove the hematoma and completely stop bleeding.

2. Spinal cord edema

Often caused by surgical operation of the injured spinal cord, the clinical manifestations similar to hematoma, treatment with dehydration, hormones, severe cases can be re-operation, open dura.

3. Cerebrospinal fluid leakage

Due to the tightness of the dural and muscle layer suture, if there is drainage, the drainage tube should be removed in advance. If the leakage is less, the drug should be changed. If the leakage cannot stop or the fluid leaks, the fistula should be sutured in the operating room.

4. Incision infection

Cracking is generally poor, incision healing ability or cerebrospinal fluid leakage is easy to occur, intraoperative should pay attention to aseptic operation, postoperative antibiotic treatment, should actively improve the general condition, pay special attention to protein and multivitamin supplement.

Intramedullary tumor symptoms Common symptoms Intense radiculopathy Pain dysfunction Spinous process tenderness Feeling separation Biting pain Spinal cord compression

Medical history

The history of spinal glioma varies greatly. The shortest is only half a month, the longest is more than 10 years, the average medical history of children is 9.5 months, and the average medical history of people over 40 years old is 5 years. When there is trauma, When fever occurs, it may promote the development of spinal cord compression symptoms. From the medical history, it is impossible to identify intraspinal or extraspinal tumors. Generally speaking, the history of cone and horsetail tumors is longer than that of the neck and thoracic spinal cord.

First symptom

The first symptom is most common with pain (60% to 68% reported in the literature). The causes of pain are various. For example, the tumor can compress the fibers of the spinal thalamus bundle, and can invade the posterior horn cells. The corresponding nerve root and dura mater are pressed against the vertebrae. The local spinal cord may cause pain due to swelling and ischemia. The pain may be severe. It may be unilateral or bilateral, but it is often inferior to the pain caused by schwannomas. Strong, such as the patient v. radiculopathy, the nature of which is like burning, biting, stinging or twisting, it should be thought that it may be caused by posterior horn cell stimulation.

Among the first symptoms, 21% of motor dysfunction and 18% of sensation abnormalities can be bilaterally asymmetrical. Clinically, sensory abnormalities including sensory separation may be much earlier than dyskinesia, but it is not easy to be noticed by patients. It is not until the onset of dyskinesia that attention is paid. Sphincter dysfunction is rare as a first symptom.

Symptoms and signs at the time of presentation

Most patients have different degrees of physical dyskinesia when they come to the hospital. The patients have pain symptoms of 85% when they come to the hospital, 43% of those who complain of limb numbness or banding, 52% of urinary dysfunction with different degrees, and constipation. At 18%, most of them have obvious pyramidal tract signs, but no convulsions occur, and there are about 1/3 of those with obvious muscle atrophy. Theoretically, the upper glioma caused by spinal glioma does not produce typical muscles. Shrinking, but in fact it is not rare, this may be caused by the after-sales use, the tumor compresses some segments of the spinal nerve, or the patient's activity is reduced due to pain, the corresponding part of the spinous process tenderness and waist Exercise is limited, less common in cases of extraspinal tumors such as meningioma and schwannomas.

Intramedullary tumor examination

Laboratory inspection

1. Number of cerebrospinal fluid cells

Generally, they are in the normal range. Some tumors are accompanied by hemorrhage. There are red blood cells in the cerebrospinal fluid. Some intramedullary tumors show lymphocytosis in the cerebrospinal fluid. Sometimes, free tumor cells can be seen. Metastatic cancer can be found in cancer cells, but the positive rate is not. High, spinal cord tumors, cerebrospinal fluid protein is often increased, some up to thousands of milligrams, the cause of high protein is generally believed to cause cerebrospinal fluid circulation obstruction in the spinal canal caused by tumor compression, the lower the obstruction site, the higher the protein, so the horsetail Tumors often make proteins high, protein high cerebrospinal fluid color is yellow, but the number of cells is normal, called protein cell separation.

2.Queckenstedt test

The spinal cord tumor is located above the lumbar puncture to cause subarachnoid insufficiency in the spinal cord. The necking test shows that both the ascending and descending are slow, especially the decrease. If the subarachnoid space is completely obstructed, the neck test does not rise. If the tumor is located in the lumbosacral region below the lumbar puncture site, the neck test can be completely unobstructed, the high-grade tumor is compressed, the pressure rises, and the low-pressure tumor is not changed.

Other auxiliary inspection

1. Spinal X-ray film

Direct signs are tumor calcification images, which are rare in gliomas. Indirect signs are enlarged spinal canal caused by tumor compression, widened between pedicles or localized bone erosion, and multiple vertebral body edges are curved. Absorption, general signs include scoliosis, lordosis, spina bifida, etc., but many clinicians ignore spinal X-ray films.

2. Myelography

The application of advanced methods such as magnetic resonance and CT scanning, myelography has been rarely used, cerebrospinal fluid dynamics examination, spinal canal angiography will aggravate the condition.

3.CT, MRI scan

Due to the lack of specificity of intramedullary tumor symptoms, the diagnosis relies mainly on imaging examination. Before CT and MRI were published, it was often diagnosed by spinal plain film and myelography. The diagnosis was difficult and the condition was aggravated. The presence of MRI enabled intramedullary tumors. Early, simple, and reliable diagnosis, pathological properties, and imaging characteristics are different:

(1) astrocytoma: common in 10 to 50 years old, accounting for 6% to 8% of tumors in the spinal canal, most commonly in the cervical and thoracic spinal cord, mostly benign, about 7.5%, most astrocytes Tumors occur alone, type I neurofibromatosis often associated with astrocytoma, histological morphology often has two types: invasive growth of astrocytoma and localized astrocytoma, MRI often no characteristic changes, T1 It shows that the affected spinal cord is extensively thickened, and there may be a mixture of high signal (bleeding) or low signal (capsule). T2 is often a high signal. After enhancement, tumor enhancement can be seen, and the boundary with the edema zone can be seen. Some astrocytomas are absent. Intensification, the slower the growth of the tumor is less obvious, the degree of tumor enhancement is related to the increase of blood flow in the lesion area and the destruction of the spinal cord barrier, that is to say, it is related to the benign degree of the tumor. The astrocytoma is often irregular and diverse, and the tumor is enhanced. Enhancement is helpful for biopsy and surgery. Enhanced scanning can help identify cystic tumors and benign cysts of the spinal cord. It has been reported that spinal cord cysts occur in tumors in 13%, adjacent tumors in 74%, and adjacent tumors are clear in cysts. For glue The cytoplasmic cells, while the cystic fluid in the tumor is orange or high in protein, the adjacent capsules are not enhanced, suggesting non-neoplastic cystic changes. Astrocytoma can have both fresh and old hemorrhage, and its imaging findings Associated with bleeding time, acute bleeding (within 3 days) T2 image is low signal, 3 to 7 days T1 image is mainly high signal, T2 image is often mixed signal, histologically, malignant astrocytoma is rich The blood vessels are borderless with the spinal cord, so it is difficult to identify the tumor-spinal border during surgery.

(2) ependymoma: the age of good hair is 40 to 50 years old, can occur in any part of the spinal cord, the chest and neck are the most common, imaging findings and astrocytoma have a certain degree of difference, the upper end of the tumor and The combination of cystic changes at the caudal end is a common marker, but intratumoral cysts are rare, MRI is more uniform, or mixed signals. In some cases, tumors can protrude to the surface of the spinal cord, even to the subarachnoid space.

(3) vascular reticuloma: not common, reported to account for 2% of spinal cord tumors, all occur in the intramedullary, divided into two types: 1 completely located in the intramedullary spinal cord; 2 soft membrane tumors, partially protruding to the spinal cord On the surface, tumors occur in adults aged 30-50 years, more common in men, often in von Hippel-Lindau disease, vonHippel-Lindau disease, 5% with spinal cord vascular reticuloma, 36% to 60% with intracranial blood Reticulocyte tumor, intramedullary vascular reticuloma often combined with syringomyelia, tumor has many sacs, it has been reported that the tumor has cyst or lesion upper and lower spinal cord thickening accounted for 67%, imaging findings cystic lesions, on the wall With nodules, T1 is a low signal with a clear boundary, and T2 is a high signal, which enhances the visible enhancement of visible tumor nodules.

(4) lipoma: rare, can occur in the spinal cord or terminal filament, T1, T2 are high signals, fat suppression can identify bleeding or fat.

(5) metastatic cancer: metastatic cancer mainly involves vertebral or epidural tissue, intramedullary metastatic carcinoma is rare, intramedullary metastases account for 1% of central nervous system metastases, including: lung cancer, breast cancer, lymphoma, colon Cancer, head and neck tumors, adrenal tumors, etc., the most common thoracic segment, acute onset, imaging lesions are more limited, long T1, long T2, visible irregular enhancement, some cases of schwannomas can occur in the spinal cord, However, it is rare. Spinal extramedullary schwannomas can also involve several spinal cord stages. It should be differentiated from intramedullary tumors. Enhanced scanning is meaningful, especially in axial scans. Tumors are often seen through the intervertebral foramen.

Diagnosis and diagnosis of intramedullary tumor

diagnosis

In addition to detailed medical history and repeated verification of existing signs, it should be supplemented with the necessary auxiliary examinations, such as spinal X-ray film, except for the presence of vertebral lesions, the most commonly used method in clinical, spinal computed tomography and magnetic Resonance.

Differential diagnosis

Spinal cord tumors are often distinguished from several spinal cord diseases.

1. Spinal arachnoiditis: The main manifestations of this disease are: long course of disease, many cases of infection, fever or trauma before the disease, the condition may have ups and downs, the symptoms may be relieved, most of them have more extensive root pain but more serious, dyskinesia More sensory disturbances are more serious, deep sensory disturbances are often more obvious than shallow sensory disturbances, sensory planes are not constant, and asymmetry, autonomic nerve function is generally late, cerebrospinal fluid examination: bacterial number is slightly elevated, protein is increased, X-ray The film is normal, the contrast agent in the myelography is scattered in the shape of beads, and there is no obvious obstruction surface, which can be distinguished from the spinal cord tumor.

2. Spinal tuberculosis: often accompanied by other parts of tuberculosis or previous history of tuberculosis, examination of the spine has more kyphosis, X-ray plain film can be seen in the spine has broken the intervertebral space narrowed or disappeared, there is a cold abscess shadow next to the spine, can and Identification of spinal cord tumors.

3. Transverse myelitis: This disease has a history of infection or poisoning, rapid onset, may have prodromal symptoms such as fever, paraplegia can occur rapidly within a few days after onset, cerebrospinal fluid cells increase, lumbar puncture and neck test It is not obstructed, so it is easy to distinguish from spinal cord tumors.

4. Epidural abscess: more onset or subacute onset, more history of suppurative infection, pain is sudden persistent severe pain, may have fever, bloody leukocytosis, but chronic epidural abscess and spinal cord Tumors are often difficult to distinguish, and the number of cerebrospinal fluid cells and protein are increased. If the abscess is located in the lumbar region, lumbar puncture may have pus outflow, and the lesion often spreads in the spinal canal and the segment is longer.

5. Disc herniation: especially cervical spondylotic myelopathy with disc herniation, or atypical chronic development of lumbar disc herniation, the development of spinal cord compression and spinal cord tumors are very similar, early root pain appears gradually spinal cord compression symptoms, and Spinal cord tumors identify the following:

(1) The history of intervertebral disc prolapse has many cases of spinal trauma.

(2) cervical disc herniation occurs mostly in the neck 5 ~ 6, the lumbar intervertebral disc prolapse occurs in the waist 4 ~ 5 or waist 5 1, the traction symptoms can be alleviated.

(3) examination of cerebrospinal fluid, protein is normal or slightly increased, X-ray plain film can be seen narrowing of vertebral body space.

6. Cervical spondylosis: Most of the degenerative lesions occur in middle-aged and elderly people. Early symptoms are mostly numbness and weakness in one side of the upper limbs, neck pain and limited mobility. A few cervical-cervical spondylotic diseases are carefully excluded, and the symptoms can be alleviated by traction. X The plain film can be seen in cervical vertebra hyperplasia and narrowing of intervertebral space, which is easy to distinguish from spinal cord tumor.

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