Spinal tumors and back pain

The last decade is characterized by an increase in the total number of oncological diseases, an increased level of their diagnosis and treatment. The capabilities of magnetic resonance imaging and radioisotope scanning allow us to establish the localization and prevalence of tumor lesions quite early, including before the appearance of clinical symptoms of the disease. This fully applies to the problem of tumor lesions of the spine, so it is quite natural that in recent years classifications of tumors of the spine have appeared that are based not only on a detailed histomorphological analysis of the pathology. Increased technical capabilities of surgical treatment have led to the appearance of anatomical and surgical classifications, which are also the basis for tactical schemes of surgical treatment. In most modern schemes of combined treatment of malignant tumor lesions of the spine, the role of surgical intervention is leading, and the appearance of neurological complications in the patient raises the question of the need for an urgent operation.

Morphological classifications of spinal tumors are based on histological examination data of the affected area.

Anatomical classifications of spinal tumors are based on the determination of the affected area, its spread within the vertebra and tissues in contact with the spine. Anatomical classifications, on the one hand, are based on general oncological principles of disease staging (McLain and Enneking classifications). On the other hand, these classifications take into account the features of intraorgan microcirculation and the ways of tumor process spread. This allows them to be considered tactical and surgical, and in accordance with them to determine the volume and nature of surgical intervention (WBB and Tomita et al. classification).

RF McLain identified several anatomical zones of the vertebra and stages of its tumor lesion, with the principle of "zonal" division being determined by the relationship of the tumor localization to the spinal canal. In turn, stages A, B and C of tumor growth were defined as intraosseous, paraosseous and extraosseous spread of the tumor, and the author also attributed its extraorgan metastasis to stage C.

Morphological classifications of spinal tumors

Classification Galli RL, Spait DW Simon RR, (1989)
I. Tumors of the skeletal system
Tumors of chondroid (cartilaginous) origin	a) osteochondroma, b) chondroma, c) chondroblastoma, d) chondrosarcoma, d) chondromyxoid fibroma
Osteogenic tumors	a) osteoma, b) osteoid osteoma, c) osteoblastoma, d) osteogenic sarcoma, d) periosteal ossifying fibroma
Resorptive processes	a) bone cyst, b) diffuse fibrocystic ostitis, c) fibrous dysplasia, d) giant cell tumor
II. Tumors of various origins
Originating from bone marrow	a) Ewing's tumor, b) multiple myeloma, c) chloroma or chloroleukemia, d) histiopytoma, d) eosinophilic granuloma, e) reticulosarcoma.
Metastatic	For lymphosarcoma, neuroblastoma, sarcoma, thyroid, breast, prostate and kidney cancer
Invasive	a) chordoma, b) angioma and angiosarcoma, c) fibroma, fibrosarcoma from fascia or nerve sheaths, d) myosarcoma, d) synovioma
Classification Boriani S., Weinstein J.N., 1997
I. Primary benign tumors of the spine	a) osteochondroma (exostoses), b) osteoblastoma and osteoidosteoma, c) aneurysmal bone cyst, d) hemangioma, d) giant cell tumor, e) eosinophilic granuloma
II. Primary malignant tumors of the spine	a) malignant multiple myeloma and solitary plasmacytoma, b) primary osteosarcoma, c) secondary osteosarcoma that develops during malignancy of benign tumors, or osteosarcoma that develops as a complication of radiation therapy (the so-called “induced” tumor), d) Ewing's sarcoma, e) chordoma, g) chondrosarcoma, h) lymphoma (non-Hodgkin's).
III. Spinal lesions in leukemia
IV. Metastatic lesions of the spine

Currently, many authors consider eosinophilic granulomas not as true tumor lesions, but as a variant of a specific disorder of cellular immunological reactivity, occurring with local tissue damage - the so-called Langerhans cell histiocytosis.

WF Enneking et al. (1980, 1983) used a different concept of "staging", defining it as the degree of invasiveness of the growth of a bone vertebral tumor. It should be taken into account that this classification was created before the advent and introduction of MRI into diagnostic practice. According to Enneking, the latent stage S1 (from the English stage) corresponds to a clear delimitation of the tumor from the surrounding bone tissue by the so-called "capsule" and a clinically asymptomatic course. At this stage, pathological fractures may occur or the tumor may be accidentally detected during routine radiography. The active growth stage S2 is characterized by tumor growth, causing gradually increasing back pain. The tumor extends beyond the vertebra, its growth is accompanied by the formation of a pseudocapsule, formed due to a perifocal inflammatory reaction and vascular ingrowth into soft tissues. The aggressive growth stage S3 is characterized by thinning of the tumor capsule, its ruptures, or the absence of tumor delimitation from the surrounding tissues. The pseudocapsule is pronounced, the adjacent soft tissues are abundantly vascularized. Pathological fractures of the vertebra and compression of the spinal cord are often clinically detected.

An even more detailed surgical classification of spinal tumors has been developed, called WBB after its authors JN Weinstein, S. Boriani, R. Biagini (1997). This classification is zonal-sectoral, since it is based on determining the position of the tumor in a zone or sector identified on a cross-section of the spine.

The zones defined by the authors correspond to the following location (or spread) of the tumor: zone A - soft tissue paraosseous; zone B - superficial peripheral intraosseous; zone C - deep intraosseous ("central") localization (the tumor is adjacent to the spinal canal); zone D - extraosseous epidural location; zone E - extraosseous intradural position. In the presence of metastatic lesions, the designation M is introduced.

In addition, the cross-section of the spine is divided into 12 sectors, corresponding to the sectors of a clock face. Taking into account the intraorgan microcirculation, the location of the malignant tumor within a particular sector allows us to determine the required volume of ablastic resection of the vertebra, as well as to identify the zones subject to resection en block (in a single block):

• damage to sectors 4-9 (with damage to at least one of the roots of the arch) is an indication for extirpation of the vertebra, in which case the removal of the vertebral body is performed en bloc, while the posterior elements can be removed in fragments;
• damage to sectors 3-5 or 8-10 is an indication for resection of 3/4 of the vertebra, in which case hemivertebralectomy on the affected side is performed en bloc, and the contralateral part of the arch is removed in fragments. The contralateral part of the vertebral body can be preserved;
• The defeat of sectors 10-3 is an indication for block removal of the entire vertebral arch. It should be emphasized that in case of defeat of sectors 10-3 the operation can be performed from an isolated posterior approach, in case of any other tumor localization the resection of vertebrae is always performed from two separate approaches to the anterior and posterior parts of the spine.

Japanese authors (Tomita K. et al., 1997) proposed their own division of the vertebra into anatomical zones. According to this division, there are 5 zones in the spine: 1 - the vertebral body, 2 - the roots of the arches and articular processes, 3 - the spinous and transverse processes, 4 - the spinal canal, 5 - extravertebral localizations, including paravertebral tissues, the disc and muscular-ligamentous apparatus of the spine. Taking into account their own division of the vertebra into anatomical zones, the authors proposed a surgical classification of spinal tumors, according to which three types of tumor lesion are distinguished: type A - intraosseous tumors with damage to: 1 - one of the three intraosseous zones; 2 - the root of the arch and zone 1 or 3; 3 - all three intraosseous zones - 1 + 2 + 3; Type B - extraosseous tumor spread: 4 - any intraosseous localization + spread to the epidural space, 5 - any intraosseous localization + paravertebral spread, 6 - involvement of the adjacent vertebra; Type M: 7 - multiple (polysegmental) lesions and skip metastases (intraorgan or "jumping" metastases). The above classification served as the basis for the polysegmental (multilevel) spinal resections developed by K. Tomita. The author performs these interventions, including one-stage en block resection of several vertebral bodies, from the posterior approach using original surgical instruments.

It should be noted that polysegmental lesions of the vertebrae are typical for systemic oncological diseases.