Last updated date: 25-Apr-2023
Originally Written in English
Primary tumors, which arise from the spine and its surrounding structures, and secondary (metastatic) tumors of distant organs, which spread hematogenously and lymphatically and are found in the spine and its surrounding tissues, are the two types of spine tumors studied. The spine is predisposed to metastasis because it is strongly vascularized and has a close association with regional lymphatic and venous drainage systems (particularly Batson's venous plexus). The most prevalent type of tumor in the spine is metastatic tumors (which account for 96 percent of all cases). Adenocarcinomas, which most commonly arise in the lung, breast, prostate, kidney, gastrointestinal tract, and thyroid, are known to spread to the spine. It was shown that between 55 percent and 70 percent of cancer patients had experienced bone metastases before death, with the number rising to 85 percent in the case of breast cancer. Surgery can be used to treat up to 15% of individuals with symptomatic spinal metastases. The thoracic and thoracolumbar spines are the most common locations for spine metastasis (70 percent), with the lumbar spine and sacrum accounting for more than 25 percent of metastatic lesions. The cervical spine is a less common location for metastases.
The true incidence of primary tumors of the spine is unknown because they are uncommon and most of these lesions are asymptomatic. The incidence of hemangiomas and enostoses, which were once thought to be the most frequent primary tumors of the spine, is believed to be between 12 and 14 percent. This ratio has been discovered to be reliant on lesions discovered by chance while doing diagnostic procedures for other reasons. The use of unnecessary diagnostic procedures will be avoided if these asymptomatic lesions, which are quite frequent in the spine and do not require treatment, are properly diagnosed. Except for a few primary tumors (osteoblastoma, chordoma) that tend to affect the spine, malignancies originating from the skeletal system are rarely seen in the spine. It's critical to distinguish primary spinal tumor from infections, especially spinal infections. Primary malignant tumors of the spine are the spine's least common tumor type. Only 12% of all bone and soft tissue sarcomas have a relationship to the spine.
Types of Spinal Tumor
Back pain is caused by four types of spinal tumors: vertebral column tumors, intradural-extramedullary tumors (in the membranes that surround the spinal cord), intramedullary tumors (within the spinal cord), and extradural tumors (outside the spinal cord) (between the membranes and bones of the spine). There are a few spinal tumors that develop in the nerves of the spinal cord, the most common of which are ependymomas and various gliomas.
A primary spinal tumor is a malignancies that begin in the spinal tissue. A secondary spinal tumor is a tumor that have migrated to the spine from another location. Tumors in the breast, prostate, lung, and other organs can migrate to the spine.
Spinal Tumor Causes
Primary spinal tumor has no recognized cause. Certain hereditary gene mutations cause some primary spinal tumor.
Blood vessels, vertebrae of the spine, meninges, nerve roots, and spinal cord cells can all be affected as a tumor grows. The tumor may potentially cause injury by compressing the spinal cord or nerve roots. The harm may become irreversible over time.
Spinal Tumor Symptoms
Medical histories and physical examination results in patients with a spinal tumor are not always linked to the current condition. However, in order to provide the physician with some hints regarding the disease, these data must be thoroughly examined and evaluated. Pain is the most prevalent and prominent symptom in patients with a spinal tumor. Patients with a spinal tumor, like patients with almost other skeletal system tumors, believe that their pain is related to a recent traumatic incident, whether real or assumed. This condition can imply a pathological fracture, which is caused by the vertebral body collapsing as a result of current degradation as a result of mild trauma. The most common indicator of a spinal tumor is pain that begins gradually, steadily worsens, is frequently persistent at night, and finally troubles the patient even when they are at rest. A pathological fracture is defined as acute pain that begins without any trauma in a patient who has had no previous symptoms. Pain in a spinal tumor can be caused by a variety of factors. A tumor that forms inside the vertebral body and expands causes bone remodalization and cortex thinning at first, later pathologic fracture and paravertebral structural invasion. The main source of discomfort at the start of the disease is a stretched periosteum caused by cortical enlargement. Following the occurrence of the fracture, discomfort from neural compression, neurological impairments, and instability arise. Waist and back discomfort are very frequent in the general population. Local tenderness is seen in the majority of individuals with the spinal tumor, which is a sign not seen in non-traumatic spine issues. Because of the pain, benign tumors in children can cause secondary scoliosis or torticollis. A kyphotic posture might be found in the setting of a pathological fracture.
Radicular symptoms are common in people with a spinal tumor. Radicular symptoms can also occur as a result of the tumor invading or compressing the nerve root, and pathologic fractures can cause root discomfort. It's crucial to assess the processes that led to the development of a neurological deficiency in patients who have had one. A patient with a quick onset of paraparesis and paraplegia who previously had pain and a patient who acquired a neurological deficit in months have vastly different prognoses and tumor behavior.
Another factor to consider while examining patients with a spinal tumor is their age. Hematological cancers and metastatic malignancies, which are the most prevalent tumors of the spine, are usually seen beyond 50 years of age.
Benign primary bone tumors such as hemangiomas, eosinophilic granuloma, osteoid osteoma, osteoblastoma, aneurysmal bone cyst, and giant cell tumor should be regarded in the foreground in cases under the age of 18. Osteosarcoma and Ewing's sarcoma are the most frequent malignant tumors in young patients.
The current and probable cancer and carcinogen contact history must be investigated when examining patients with a spinal tumor. There have been cases of patients who developed spinal metastases years after completing cancer treatment.
Spinal Tumor Diagnosis
Spinal Tumor X Ray
In the case of spinal disorders, plain radiographs should always be the first line of imaging. Other regions of the spine and pelvis, in addition to plain radiography of the suspicious location, must be checked in patients with suspected spine malignancies. Plain radiographs can assist identify approximately 85% of benign tumors, as well as some malignant tumors and metastatic lesions, which have a more specific appearance. In 45% of individuals with spine metastases, plain radiographic signs are observed. For a destructive spine lesion to be visible on plain radiographs, at least 55% of the trabecular bone must be lost. Plain radiographic signs in many hematological malignancies may not be visible until late in the disease's progression. Metastatic lesions might have osteoblastic, osteolytic, or mixed radiographic features. Prostate and breast carcinoma spine metastases are typically osteoblastic or mixed-type lesions, whereas lung and thyroid carcinomas, as well as renal cell carcinoma, are typically lytic metastatic lesions.
Radiopaque lesions that extend beyond the rectangle that defines the vertebral body's borders are usually initial malignant lesions of the spine, such as osteosarcoma or chondrosarcoma. A small shadow limiting the appearance of one pedicle on an anteroposterior radiograph, known as the winking owl sign, suggests that the tumor mass has spread from the vertebral body to the paraspinal area. The winking owl sign is the most common direct radiographic marker of a metastatic lesion. The presence of one or more lytic lesions is another common radiographic evidence for the spinal tumor. Bone destruction is indicated by lytic lesions. However, the nature of the tumor in the spine, as well as all bone tumors, can be determined by the destruction pattern. Geographical destruction indicates a slower progression of the tumor, moth-eaten lesions indicate a faster progression of the tumor, and permeative destruction indicates a rapid progression of the tumor. The collapse of the vertebral body, also known as compression fracture, is another common radiographic feature. It's difficult to tell the difference between pathological and benign osteoporotic compression fractures. In circumstances where simple radiographs are negative or questionable, bone scintigraphy is the most useful diagnostic method. Radioisotopes are used in bone scintigraphy, which is a diagnostic process. Even though bone scintigraphy has a low specificity except in a few malignancies like osteoid osteoma, it is a valuable diagnostic tool due to its high sensitivity and ability to scan the entire body, which is not available with other diagnostic methods. It can also be used to guide biopsy and identify the primary disease in metastatic cancers with unclear primary origins.
Spinal Tumor CT Scan
In the assessment of mineralized tissues, computed tomography (CT) is the most advantageous method. CT, which is superior to conventional radiography in terms of its capacity to examine complicated anatomical structures like the spine in three dimensions, can be used to analyze even complex anatomical structures like the spine. However, the method's inadequate affinity and efficacy in soft tissue tumors are limitations.
Spinal Tumor MRI
In the examination of bone marrow and spinal canal, tumor relation with neurovascular structures, and tumor vasculature, magnetic resonance imaging (MRI) outperforms all other diagnostic methods in spine malignancies. MRI is a good tool for examining adjacent levels with large, cross-sectional sagittal images in individuals with spinal canal involvement. Neurological deterioration in adjacent or distant levels has been observed in 12% of spine metastases with spinal canal invasion. The ability of the MRI to distinguish between osteoporotic compression fractures and pathological spinal fractures is crucial. Pathological fractures show low signal intensity on T1-weighted scans and high signal intensity on T2-weighted scans, although osteoporotic compressions show low signal intensity in both scans, despite the lack of consensus so far. This discovery, however, does not apply to acute osteoporotic fractures. Due to edema and congestion inside the trabecular bone, osteoporotic compression fractures in the acute condition (3-6 weeks following the fracture) would display low signal intensity on T1-weighted scans and high signal intensity on T2-weighted scans. The bone marrow signal pattern should be investigated in such circumstances. Intra- and extradural tumors, as well as intra- and extramedullary tumors, can be distinguished using gadolinium contrast-enhanced MRI.
Spinal Tumor Biopsy
The biopsy is the final and most important step in the diagnosis of the spinal tumor, especially those with an unclear primary origin. All diagnostic techniques should be used rationally before planning the biopsy, and the precise location of the lesion should be identified. Fine needle aspiration, true-cut biopsy, incisional or excisional biopsy are all options for spinal tumor biopsies. Percutaneous methods such as fine needle biopsy and true-cut biopsy are used. It's important to remember that tumor cells contaminate biopsy routes, thus biopsies must be done far away from neurovascular structures through small incisions that can eventually be removed alongside the tumor mass in a definitive surgical procedure.
Spinal Tumor Treatment
Spinal Tumor Surgery
The major goal of treatment for spine tumors is local disease control and at least one-year of survival for spine metastases. The most effective treatment for the pain and neurological problems produced by spinal instability is surgery. Indications for surgery include spinal instability, vertebral collapse with or without neurological deficits, radiotherapy-resistant malignancies, excruciating pain unresponsive to conventional therapy, and neurological impairment prior to, during, or after radiotherapy. Decompression of tumor compression to the spinal cord, establishment of a tumor-free solid spine, and minimal morbidity are the general principles of spinal tumor surgery.
Palliative surgical methods in metastatic spine tumors include posterior spinal canal decompression with posterior instrumentation, restoring vertebral body bone loss with cement augmentation techniques, and total spondylectomy with anterior and posterior stabilization. In addition to these surgical methods, total/partial laminectomy, total/partial vertebral body resection, piecemeal resection, and curettage can be utilized to treat a primary spinal tumor.
Total spondylectomy, also known as vertebrectomy, is a large excision technique for spine tumors that can be done in one or two stages. In a two-stage total spondylectomy, posterior instrumentation is used first, followed by total laminectomy via bilateral pedicle section. The patient is then put into a supine position and the vertebral body is removed using an anterior approach. Segmental nerve roots and vessels, as well as caudal and cranial discs, are ligated and dissected during total spondylectomy. The anterior defect must be repaired once the vertebral body has been removed. Tomita et al. established a one-stage complete en bloc spondylectomy. After forceful dissection of the vertebral body from nearby structures and major vessels that lie anterior to the spinal column, the vertebral body is removed by a posterior approach.
In the spinal tumor, radical resection is difficult. Total removal of the affected level vertebral body, as well as that level of the dural sac, spinal cord, and spinal nerves, is required under surgical oncologic principles. Despite the fact that it is exceedingly morbid, this surgery is rarely performed as a salvage operation.
Benign Spinal Tumor
The most frequent primary benign spine tumors include osteoid osteoma, osteoblastoma, osteochondroma, giant cell tumor of the bone, aneurysmal bone cyst, eosinophilic granuloma, and neurofibroma. The primary benign spinal tumor is more common than primary malignant tumors. Relapse is common in benign aggressive tumors including giant cell tumors of the bone, osteoblastoma, and aneurysmal bone cyst. As a result, local adjuvant medications and marginal resection must be used in the operative treatment of these tumors.
Osteochondromas, like other benign tumors of the spine, arise from the posterior elements and become symptomatic when the spinal canal is compromised or the nerve roots are compressed. It's important to remember that if the osteochondromas' cartilage cap isn't entirely removed, the tumor may return.
A common primary benign spinal tumor is osteoid osteoma. Osteoid osteoma is frequent in teenagers and young adults with painful secondary scoliosis and pain that increases at night and is alleviated by nonsteroidal anti-inflammatory drugs, particularly acetyl-salicylate. The entire nidus is removed in the treatment of osteoid osteoma. After treatment, the symptoms disappear completely.
The spinal column is the most frequent site for osteoblastoma in the entire skeleton. Although osteoblastoma is histopathologically identical to osteoid osteoma, it has distinct clinical and radiological features. Osteoblastomas, like other benign tumors, usually arise from the posterior components. Osteoblastoma, unlike osteoid osteoma, can develop into the spinal canal and compress the dural sac. Osteoblastomas are treated with intralesional excision or marginal resection, depending on the histological grade. In rare circumstances, postoperative radiation may be possible in terms of local management.
The most common benign tumor of the spinal column is hemangioma. Hemangiomas mainly affect the vertebral body and are asymptomatic lesions. Hemangiomas are seen in 11% of the general population, as per autopsy data. Hemangiomas can induce pathological fractures even if they are asymptomatic. Hemangiomas can also induce symptoms during pregnancy third trimester.
In patients under the age of 20, aneurysmal bone cysts (ABC) are frequent in the posterior components of the spinal column. ABC has a propensity of involving multiple segments. ABC lesions are constantly growing and expanding, whether they are active or aggressive (stages 2-3). ABC is treated with embolization or extensive resection following embolization. ABC has a 30 percent overall recurrence rate.
The sacrum is more typically affected by giant cell bone tumors (GCT) than other regions of the spinal column. Because of their location within the vertebral body, obtaining clean surgical margins in the surgical treatment of GCTs is challenging. Because piecemeal resection is accompanied by a 50% recurrence risk in surgical therapy of GCT, surgical margins should aim for extensive resection. Because of the high likelihood of sarcomatous transformation, postoperative radiation for local control is contentious. Secondary osteosarcoma is the most common consequence of this transformation. Even though GCT is a benign tumor, it can spread to the lungs.
Eosinophilic granuloma is a benign tumor that most commonly affects children and teenagers. The vertebral body flattens uniformly and quickly as a result of eosinophilic granuloma. Vertebra plana is the radiological characteristic of this type of vertebral body involvement. It always resolves on its own. The traditional treatment is kyphosis prevention with observation and, in some situations, bracing.
Malignant Spinal Tumor
Osteosarcoma, Ewing's sarcoma, and chondrosarcoma are the three most common primary musculoskeletal system sarcomas found in the spinal column. These tumors can appear anywhere along the spinal column. Children and teenagers are more likely to develop osteosarcoma and Ewing' sarcoma, but adults and older people are more likely to develop chondrosarcomas.
Patients between the ages of 7 and 20 are more likely to develop Ewing's sarcoma. Because of Ewing's sarcomas' inflammatory nature, it's possible that it'll be misinterpreted as an infection, delaying its detection. Swelling, localized pain, fever, and an elevation in sedimentation rate are all common symptoms in Ewing's sarcoma patients. Only 6% of Ewing's sarcoma patients have involvement of the spinal column. Ewing's sarcoma is most typically found in the pelvis in patients with axial skeleton involvement. In contrast to long bones, where periosteal response and permeative destruction are common, the major radiological finding of Ewing's sarcoma spinal involvement is lytic lesions accompanied with soft tissue masses in the vertebral body. Ewing's sarcoma can be distinguished from spondylodiscitis by the preservation of contiguous discs. In most pediatric spinal infections, the disease begins in the disc space and progresses to the vertebral endplates, but in Ewing's sarcoma, involvement begins in the vertebral body's core trabecular bone, with endplate involvement appearing later in the tumors' invasion. Ewing's sarcomas in the extremities and spine react effectively to chemotherapy due to the high cellular proliferation of the tumor tissue. In Ewing's sarcoma, wide resection with clear surgical margins is possible following neoadjuvant treatment. In cases of contaminated surgical margins, postoperative radiation should be given.
Although osteosarcoma is the most frequent primary malignant tumor of bone, it seldom affects the spine. The spine is the source of around 3% of all osteosarcomas. The most frequent occurrence of classic osteosarcoma is in the second decade of life. Secondary osteosarcomas, which result from the sarcomatous transformation of pre-sarcomatous diseases such as Paget's disease of bone and fibrous dysplasia, may have a second peak occurrence in the sixth decade of life. The spine and pelvis are the most common sites of Paget's osteosarcomas. Treatment for osteosarcomas of the spine is identical to that for osteosarcomas of the extremities. In the last 45 years, osteosarcoma treatment has progressed. Prior to the 1970s, the 5-year survival rate for osteosarcomas was 15 percent, with 75-80 precent of patients living with no indication of disease. Osteosarcoma is currently treated with two rounds of neoadjuvant chemotherapy, followed by wide or radical resection and at least four further rounds of chemotherapy. The prognosis of a tumor is determined by its response to chemotherapy.
Chondrosarcomas are more prevalent in the spine than the other primary sarcomas. Chondrosarcoma is resistant to chemotherapy and radiotherapy due to the extremely avascular nature of cartilage tissue, therefore surgical treatment with wide or radical surgical margins is the key determinant of prognosis. The major goal of surgical treatment should be radical resection.
Chordoma is a tumor that grows from remnants of the notochordal cells and does not arise from the musculoskeletal system. Despite the fact that it is not a primary skeletal tumor, chordoma affects the spinal column and is particularly destructive to the sacrum and lower lumbar vertebrae. One of the most prevalent sacral tumors is chordoma. The sacrum accounts for 65% of chordomas, while the skull base accounts for 20%, and the rest of the axial skeleton accounts for 15%. Chordomas are more commonly found in the sacrum midline and caudal half. The most typical symptoms are constipation, coccygodynia, hemorrhoids, and urinary incontinence. In a digital rectal exam, half of the sacral chordomas are palpable. Chordoma is best assessed by MRI because it is a soft tissue tumor. Because surgical margins are so important in chordoma prognosis, wide resection should be the goal, particularly in the treatment of sacral chordoma.
The largest component of the axial skeleton that supports important organs is the spinal column. The most common malignancies that affect the spine are metastatic tumors. Benign bone tumors are the most common cancers that affect the spine, followed by metastatic tumors. Primary bone sarcomas are the least common tumors that affect the spine. It might be difficult to tell the difference between primary and metastatic tumors in the spine. In the spine, metastatic tumors of unclear origin are also common. The primary lesions' location is important in the management of the metastatic spinal tumor. As a result, in the case of initial unknown metastases, the biopsy is a vital step that influences treatment options. It's important to remember that metastatic lesions involving the spine are a part of systemic malignancy. The importance of surgical staging in deciding treatment strategy cannot be overstated. Pain alleviation with the maintenance of mechanical and neurological functions of the spine should be the goal of treatment for metastatic tumors. The elimination of local disease while maintaining the mechanical and neurological abilities of the spine should be the goal of primary tumor treatment. All diagnostic and interventional operations in primary or metastatic tumors of the spine, as well as the general management of the patient, should be done in a multidisciplinary approach, as with all oncological surgery procedures.