Spinal Tumors

Spinal tumors (tumors of the spinal cord), with their high morbidity and mortality rates (morbidity and mortality), have been the focus of interest of neurosurgery due to early diagnosis and favorable results when appropriate treatment methods are applied. In parallel with technological progress, the rates of treatment success have increased with the increase in diagnostic possibilities and the development of surgical techniques, especially microsurgery.

Approximately 25% to 25% of central nervous system tumors are spinal tumors. The incidence of spinal tumors in the population varies between 2-10/100,000. Differentiating spinal tumors according to their localization facilitates diagnosis and treatment. For this reason, the duramater (the outer layer of the spinal cord membrane) relationship is taken into account in classification. Spinal tumors are grouped accordingly as extradural, intradural extramedullary and extramedullary. The ratio of intradural to extradural is 2/3. Of all spinal tumors, 55% are extradural, 40% are intradural extramedullary and 5% are intradural intramedullary tumors.

The majority of extradural tumors are metastatic tumors. Apart from metastatic tumors, primary spinal tumors are also included in extradural tumors. Neurofibroma and meningioma constitute the majority of intradural extramedullary spinal tumors. Ependymoma, astrocytoma and hemangioblastoma constitute 90% of intradural intramedullary spinal tumors.

Spinal tumors are mostly benign tumors. In parallel with the development of early diagnosis and treatment possibilities, better results have been observed.

In recent years, there has been a great development in radiosurgery. CyberKnife radiosurgery has been beneficial in pain control and improving quality of life. The main benefits of CyberKnife radiosurgery are short treatment time, rapid recovery and favorable response to treatment. This technique can be used as a primary treatment for spinal lesions, but can also be used in inoperable cases, in patients who have received previous radiotherapy or as an adjunct to surgical technique.

While stereotactic radiosurgery and radiotherapy allow for high doses in spinal lesions, the dose to the spinal cord should be limited to the tolerance level. In the majority of postoperative patients with initial neurodeficit who underwent radiosurgery, the picture was either stable or improved.

General Clinical Findings and Diagnostic Methods

The majority of extramedullary tumors are benign and grow slowly, thus making room for themselves in other words. Symptoms depend on the location and are mostly in the form of compression of adjacent neural formations. Dorsal and dorsolateral localizations are characterized by posterior and lateral cord compression. Occipital pain, loss of strength and sensation in arms and legs, atrophies are observed in upper cervical localization. They may cause hydrocephalus as a result of decreased absorption and flow due to increased protein in the cerebrospinal fluid. Tumors located completely laterally cause Brown-Séquard syndrome characterized by motor and posterior cord loss on the same side and sensory loss on the opposite side. In general, spasticity, ataxia, sphincter and sexual disorders are added to these findings in late periods. Asymmetric radicular lower extremity pain and sensory loss in tumors located in the filum terminale indicate Cauda Equina involvement.

Symptoms in intramedullary tumors show a rapid and sometimes acute course of a few weeks/months, which is due to frequent bleeding, especially in ependymomas. Motor and sensory deficits depend on localization and pain is blunt. Symptoms of sphincter disorders and sexual incompetence appear earlier.

Magnetic resonance imaging (MRI) is largely used in the diagnosis and many tumor-related features such as location, intensity, staining characteristics and invasion can be detected. All these features provide detailed information about the pathology of the tumor and are also important for surgical planning. Computed tomography (CT) is more helpful in determining the tumor-bone relationship. Spinal angiography provides clarification of nonneoplastic lesions of vascular origin, such as arteriovenous malformations and aneurysms, and is important for surgical decision-making and planning.

Treatment Options

Surgery is the first and most important treatment modality for intradural spinal tumors. While total resection of these tumors, which are mostly benign, provides complete recovery, it is mandatory for the pathological diagnosis of malignant tumors. Regardless of age, surgery is the first option even in tumors accompanied by advanced and established neurological findings. Transoral, transcervical (vertebrectomy), extreme lateral transcondylar and atlanto-occipital transarticular procedures have been described and used for resection of tumors located ventral to the foramen magnum and craniocervical junction. However, some of these interventions may cause instability and may require additional stabilization operations. Except for this specific location, classical laminectomy/laminotomy is an adequate approach for the majority of intradural tumors. Again, bipolar coagulation and microdissection are sufficient to remove a significant proportion of tumors. Ultrasonic aspirators are used to shrink the tumor from within. Peroperative monitoring with motor and sensory evoked potential recordings is also used in the surgical process. In addition to general complications related to surgery and anesthesia, worsening of neurological findings, cerebrospinal fluid fistulas, infections, hematomas and instability are the complications that may be encountered. Radiosurgery is another option used by some centers. Radiotherapy is used in addition to surgery for primary malignant tumors, droplet and disseminated metastases. Classically, total 30-50Gy / 28-30 days fractionated. Higher doses may cause radiation necrosis. Chemotherapy is also used as an additional treatment option in malignant tumors, similar to intracranial tumors. Generally, temozolamide and PCV (procarbazine / CCNU / vincristine) are administered as different regimens.

I.I. Intradural - Extramedullary Spinal Tumors

Intradural extramedullary tumors constitute 40% of all spinal tumors and approximately 70% are caused by meningioma and schwannoma; 90% are benign and can be completely removed and 0-10% of them are associated with worsening neurological status. Microsurgery provides safe and successful results in tumors in this region. However, alternative techniques should not be ignored in patients with neurofibromatosis, recurrent tumors, multiple lesions and high surgical risk. CyberKnife Radiosurgery is a safe and low morbidity technique for benign intradural extramedullary tumors.

I.I.A. Meningiomas

Spinal meningiomas are less common than intracranial ones, accounting for approximately 7.5-12.7% of all meningiomas. They constitute approximately 25-46% of all intradural-extramedullary tumors. It is a benign tumor. It is common in the 50s and 60s. The female to male ratio is 4-5/1.

It is localized in 67-84% thoracic (back), -27% cervical (neck), 2-14% lumbar (waist) region. In women, the density was found especially in the thoracic region.

It is usually intradural extramedullary (83-94%) localized; however, it can also be seen as extradural in 3-9% and as masses with intadural/extradural components in 5-14%. The risk of malignant transformation is high in those that are completely extradural.

Pain is the most common and early symptom. With the routine use of Magnetic Resonance Imaging (MRI), the time to diagnosis has shortened and surgery can be performed without severe neurologic deficits.

 82-99% can be completely removed. Postoperatively, there is a sustained improvement over a period of several months. It has a good prognosis. Although recurrent meningiomas are rare, they have been observed between 1.3-6.4% in different series. If benign, radiotherapy and chemotherapy are usually not required. Radiotherapy after subtotal resection (partial removal) is controversial. Radiotherapy can be applied in recurrent meningiomas. Mortality and morbidity rates are low (0-3%).

I.I.B. Schwannoma / Nörofibroma:

Nerve sheath tumors (neurinoma, neurofibroma, neurolemmamo and schwannoma) are tumors originating from schwan cells and are common in the general population (0.3-0.5/100,000). They are common in the 30-50s and although gender predominance is not observed, it has been reported in different series that they are slightly more common in women than in men.

It is most commonly located in the thoracic, cervical and lumbar regions, respectively. More than 90% are benign. They are slow growing tumors. 80% have pain and 80% have weakness, sphincter problems and sensory disturbances.

The goal is complete removal of the tumor. In this case the prognosis is extremely good. Since they are of nerve root origin, they need to be dissected and the root cut if necessary, they almost never cause serious functional problems. Recurrences usually occur after subtotal resection. There is no indication for radiotherapy after surgery.

In a study of post operative (after surgery) long term results; 76.59% of the cases showed improvement, .02% showed partial improvement, 4.25% showed no change, 0.7% showed deterioration and 1.41% died.

I.II. Intradural Intramedullary Spinal Tumors

Of these, 45% are astrocytomas and 35% are ependymomas. Intramedullary spinal tumors constitute approximately 20-30% of all intradural spinal tumors in adults, while this rate varies between 40-50% in children.  Hemangioblastoma is the 3rd most common intamedullary tumor. Other tumors in this group are embryogenic tumors (dermoid, epidermoid, teratoma), neuronal tumors (oligodendrioglioma, ganglioglioma) and lipomas.

While emphasizing the importance of preoperative (preoperative) neurological status in terms of outcome, he also stated that tumors in the thoracic (back) region increase the risk of postoperative (postoperative) morbidity.

I.II.A. Astrocytomas:

More common in children and young people. It is more common in males than females. Thoracic and cervical regions constitute the majority in terms of localization. There is usually multi-site involvement. Approximately half of them contain cystic areas.

The most common initial symptom is pain, which usually corresponds to the location of the tumor and tends to increase with movement and at night. The benign to malignant (good to bad) ratio is 3/1.

Although complete removal of the tumor is aimed, it is usually not possible. It is recommended to drain it with an ultrasonic aspirator without damaging the normal neural tissue. Radiotherapy is recommended after surgery for high grade and recurrent tumors.

I.II.B. Ependymomas

Ependymomas are the most common intramedullary tumors in adults and second most common in children. They are common in 30 and 40 years of age. Male to female ratio is 2/1. 90% are located in the lumbosacral region followed by the cervical region.

The most common complaint is pain and loss of strength in one extremity. It often presents as neck and back pain. Neurologic deficits are usually encountered in the late stages of the disease and in case of delayed diagnosis.

Results are good in total resections and recurrence is possible in subtotal (partial) resections. The prognosis is very good Ependymomas are sensitive to radiotherapy and this additional treatment is successful against local recurrence and metastases. Chemotherapy is restricted to recurrent cases where radiotherapy and surgery are not feasible.

I.II.C. Others

Hemangioblastoma:

60% of this benign tumor is intramedullary; it is more common in the thoracic and cervical regions. The mean age is 35 years and most cases are usually under 40 years of age. There is no gender difference. Its well-circumscribed nature allows surgical removal.

II. Extradural Spinal Tumors

II.I. Metastatic Extradural Tumors

Skeletal metastases are most common in the spine. The most common primary sources are: lung, breast, prostate, kidney, thyroid, gastrointestinal tract and lymphoma. Lung and prostate are the most common primary sources in men; breast and lung are the most common primary sources in women.

These tumors are seen in 60% of men and 40% of women and peak between the ages of 40-65 (10,40). Metastases are most commonly seen in the lumbar region, less commonly in the thoracic region and least commonly in the cervical region.

It has been reported that the mean duration of symptoms is 2 months, they are frequently localized in the thoracic and lumbar regions, the most common initial complaint is pain, paraplegia (paralysis) may develop at a rate of -15% and the most common primary focus is usually the lung.

Spinal metastases; 95% are extradural, most of the rest are intradural extramedullary (4%) and rarely intramedullary metastases (1%).

More than half of the cases have motor loss (weakness) and about half have sphincter problems and sensory disturbances.

In 90% of cases with symptomatic spinal metastases, direct radiographic findings are found. Bone scintigraphy is used to identify multiple lesions and distant metastases. Computed tomography and MRI are also very important in detecting metastasis, differential diagnosis and surgical planning.

When radiotherapy and surgical resection are applied together, favorable results increase up to 44%-68%. The success of surgery varies according to the localization of the tumor. In cases of rapidly progressive paraplegia, urgent surgery should be performed, otherwise irreversible and complete spinal cord injuries may occur. Surgical decompression followed by stabilization and radiotherapy is the treatment of choice for metastatic spinal tumors.

II.II. Primary Spinal Tumors:

Primary spinal tumors are not as common as metastatic extradural tumors. Approximately '% of all primary skeletal tumors are located in the spinal region. Primary spinal tumors are characterized by invasion of adjacent tissues and compression of the spinal cord. There is a correlation between age and the benign or malignant form; those under 21 years of age are usually benign.

In radiologic diagnosis, direct radiographs are used first. MRI provides great convenience in the classification and characterization of the tumor. CT is also important in the evaluation of the bone structure.

Surgery, chemotherapy and radiotherapy are the treatment options. The aim of surgery is complete removal of the tumor without destabilization.