Spinal ependymoma is a tumor formation from the cells of the ependyma of the spinal canal, which has a different degree of malignancy. It is manifested by local pain in the spine (less often by the radicular nature of pain), sensitivity disorders, peripheral and central paresis, violation of urination, defecation. The final diagnosis is established with the help of MRI of the affected department, histological examination of tumor tissues. Surgical treatment — removal of neoplasia using microsurgical techniques. With the malignant nature of the ependymoma, postoperative radiation therapy is used.
ICD 10
C72.0
General information
Spinal ependymoma is less common than brain ependymoma. Among the adult population, it is diagnosed in 34% of cases of intramedullary spinal cord tumors. In 40% of cases, ependymoma is a tumor of the ponytail and is localized in the terminal part of the spinal canal. Relatively recently, it was proved that the ependymal formations of the ponytail belong to extramedullary tumors. As they grow, they either push apart the terminal nerve bundles, or surround them in a muff-like manner.
The ependymoma is not prone to extradural growth (sprouting beyond the dura mater). Extradural growth is observed mainly when the neoplasm is localized at the level of the sacrum. The average age of patients with diagnosed spinal ependymoma is 45 years.
Causes
The etiofactors provoking oncogenesis have not been definitively studied. Some authors suggest that ependymoma is the result of heterotopy of ependymal cells, which arose due to incomplete closure of the neural tube during embryogenesis. Most researchers assign the main etiological role to the combined effect of a number of factors common to various tumor processes. Factors predisposing to the development of a tumor are divided into 3 main groups:
- Exogenous. Oncogenic properties are possessed by radioactive radiation, food carcinogens, certain dyes and household chemicals, some metals, air polluting chemicals. Long-term effects on the body, these factors cause a change in the basic properties of its individual cells, which can lead to the emergence of neoplasia.
- Endogenous. The main internal factor contributing to the development of neoplasms is a decrease in antitumor immunity. The lack of proper antitumor protection causes the preservation of viability and subsequent reproduction of atypical (mutated) cells forming a tumor.
- Hereditary. The genetic determinacy of the occurrence of neoplasia is assumed. Hereditary predisposition to oncogenesis is confirmed by the existence of familial forms of cancer, a tendency to develop tumor formations in Recklinghausen neurofibromatosis, familial polyposis and other hereditary diseases.
Pathogenesis
An ependymoma is formed as a result of the reproduction of altered (atypical) cells forming the ependymal lining of the spinal canal. The process starts when ependymocytes acquire abnormal properties, including the ability to amplify division. In most cases, spinal ependymoma is a benign formation, its clinical manifestations are caused by compression of the spinal cord by an increasing volume of tumor tissues.
The result of spinal compression is the dysfunction of the neurons of the affected segment, leading to a violation of the innervation of the corresponding part of the body with the development of sensory disorders, paresis. Compression of the conductive tracts passing through the spinal cord causes total denervation of tissues located below the lesion level. In the case of extradural growth, the tumor process proceeds with germination into the bone tissue of the sacrum, spreading into the pelvic cavity, subcutaneous tissue of the sacral region. Malignant ependymoma is characterized by destructive growth with the destruction of spinal tissues.
Classification
According to the nature of growth, intra- and extramedullary ependymomas are distinguished. The latter include mainly the formations of the terminal parts of the spinal canal. By location, spinal ependymoma is classified into cervical, thoracic, lumbar and ponytail ependymoma. In practical neurology and neurosurgery, classification based on morphological features and the degree of malignancy of neoplasia is considered fundamental. It includes 4 main types of ependyma:
- True. Various morphological variants are known: cellular, papillary, mixed, epithelial. In some cases, the tumor forms perivascular rosettes, in others it has villi and trabeculae. True ependymoma refers to neoplasia of grade II malignancy.
- Mixopapillary. A distinctive feature is the mucosal dystrophy of tumor tissues, causing their melting with the formation of cysts. The typical extramedullary location of the tumor, localization in the area of the ponytail. The formation has the I degree of malignancy.
- Anaplastic (ependymoblastoma). The most malignant variant (grade III). It is characterized by low cell differentiation, the ability to give metastases that spread by the cerebrospinal fluid pathway.
- Subependymoma (ependymoastrocytoma). It is a benign tumor node consisting of ependymal cells and glial fibers. It is rarely found in the tissues of the spinal cord.
Symptoms
Benign ependymatous neoplasia is characterized by slow growth. The manifestation of clinical symptoms is possible after 1-1.5 years from the onset of the disease, seeking medical help occurs on average after 4.5 years. The symptoms depend on the level of the lesion. A typical manifestation of the onset of the disease is a local pain syndrome in the spine. 70% of patients complain of increased pain in a horizontal position, at night. In a number of patients, the pain is radicular in nature, although the full clinical picture does not fit into the classic radiculopathy.
Segmental sensitivity disorders are an early symptom. There may be pain dysesthesia in the form of a sensation of heat / cold in the corresponding extremities, dissociated sensory disorders (a decrease in surface sensitivity while maintaining a deep one). The progression of the tumor process is accompanied by an increase in sensory disorders, their spread to the underlying departments, the appearance of peripheral single- and bilateral paresis, and then central paraparesis below the level of neoplasia, pelvic disorders. Peripheral motor disorders occur with a decrease in muscle tone, extinction of tendon reflexes. Central paresis is characterized by spastic muscle hypertonicity, hyperreflexia.
Ependymoma of the cervical segments of the spinal cord may be accompanied by dizziness, cephalgia of occipital localization, hoarseness, paroxysmal cough, dysphagia, spastic tetraparesis. The formation of a ponytail debuts with root-type pains spreading to the lower limb on the side of the lesion. Over time, the pain becomes bilateral. Peripheral paresis of the distal parts (feet, shins), urinary retention are typical.
Complications
Progressive changes in the spinal cord lead to severe disability of the patient, restriction of his mobility. The concomitant development of trophic disorders causes the occurrence of bedsores, slight injury and infection of the skin, penetration of infectious agents into the blood. Urgent disorders associated with pelvic organ dysfunction are possible: acute urinary retention, fecal intoxication. Extradural ependymoma of sacral localization is complicated by destruction of the sacrum, tumor lesion of the pelvic organs. The most dangerous complication is the metastasis to the brain characteristic of ependymoblastoma.
Diagnostics
The localization of pain directly in the spine, the segmental nature of sensory disorders allows the neurologist to suspect a spinal neoplasm. Pronounced difficulties arise when neoplasia is localized in the lumbosacral region, since in such cases the clinic is similar to the manifestations of sciatica. Suspicion of a tumor occurs with the development of pelvic disorders, the bilateral nature of symptoms, and the low effectiveness of conservative therapy. The necessary diagnostic measures include:
- Neurological examination. During the examination, the neurologist identifies peripheral and central sensory, motor disorders. The results of the examination suggest the level of spinal cord damage, suspect the presence of a volumetric formation.
- MRI of the spine. MRI myelography serves as the “gold” standard for the diagnosis of ependyma. Additional contrasting makes it possible to study in detail the components of the formation (cysts, hemorrhages), to differentiate tumor tissues from peritumorous edema. If magnetic resonance imaging is not possible, a CT spine is performed.
- Histological examination. The study of the morphology of tumorous tissues at the microscopic level makes it possible to accurately verify ependymoma, its type, and malignancy. In most cases, intraoperative histology is performed. After the operation, additional examination of the operating material is carried out.
Ependymoma requires differentiation from vertebrogenic myelopathy, myelitis, spinal circulatory disorders, posttraumatic spinal canal hematoma, syringomyelitic cyst, spinal hemangioma. Since clinical differential diagnosis is difficult, MRI is of paramount importance. The establishment of a final diagnosis is possible only based on the results of histological examination.
Treatment
The only adequate method of treatment is radical removal. The operation is performed by a neurosurgeon using microsurgical technologies under the control of motor and sensory evoked potentials. Benign ependymoma is well separated from adjacent tissues, which makes it possible to achieve the most complete removal. The malignant nature of the formation, confirmed by the results of intraoperative histology, serves as an indication for extended resection of neoplasia. In the postoperative period, a control MRI is performed. If an undetected tumor fragment is detected, repeated surgical intervention is recommended.
Postoperative radiation therapy is used only for malignant ependyma. Surgical treatment is combined with subsequent rehabilitation therapy performed by rehabilitologists, massage therapists, physical therapy doctors. Restorative treatment has a medicinal component, including anti-inflammatory, vascular, neurometabolic pharmaceuticals.
Prognosis and prevention
The use of microsurgery, intraoperative neurophysiological monitoring allows the removal of intramedullary ependymes without increasing neurological deficit. The degree of recovery of lost functions depends on the localization, size and spread of the tumor process, timeliness, volume of the operation, completeness of rehabilitation measures. In some cases, neoplasia recurs, which requires repeated surgery associated with the risk of formation of a cerebrospinal fistula, causing the occurrence of meningitis, arachnoiditis.
Primary prevention is non-specific, includes reducing any oncogenic environmental influences, increasing immunity. Secondary prevention provides for timely detection of relapse, carried out by annual control MRI.