Risk assessment in deferred and recovered donors.

Serologic testing and Donor Risk Assessment Interview (DRAI) combined have made tissue transplantation a frequent and safe modality for a variety of trauma and disease conditions. Donate Life America reports 30,000 tissue donors providing more than 1,750,000 tissue transplants annually. This study of 188 potential donor cases addresses issues of risk assessment in a medical examiner population in a metropolitan area, where serologic testing of deferred potential donors were compared with the DRAI screening, which determined the suitability or non-suitability for tissue procurement. Such serologic testing of deferred cases is not usually available in evaluating screening processes. This comparison gives insight into the effectiveness of the DRAI screening in deferring potential serology reactive donors. Results show in 65 cases how the DRAI screening eliminates most, but not all of the serologically reactive donors identified post recovery. The result emphasizes the need for the combined process of DRAI screening and testing to assure transplantation safety.

Could automated machine-learned MRI grading aid epidemiological studies of lumbar spinal stenosis? Validation within the Wakayama spine study.

BACKGROUND: MRI scanning has revolutionized the clinical diagnosis of lumbar spinal stenosis (LSS). However, there is currently no consensus as to how best to classify MRI findings which has hampered the development of robust longitudinal epidemiological studies of the condition. We developed and tested an automated system for grading lumbar spine MRI scans for central LSS for use in epidemiological research. METHODS: Using MRI scans from the large population-based cohort study (the Wakayama Spine Study), all graded by a spinal surgeon, we trained an automated system to grade central LSS in four gradings of the bone and soft tissue margins: none, mild, moderate, severe. Subsequently, we tested the automated grading against the independent readings of our observer in a test set to investigate reliability and agreement. RESULTS: Complete axial views were available for 4855 lumbar intervertebral levels from 971 participants. The machine used 4365 axial views to learn (training set) and graded the remaining 490 axial views (testing set). The agreement rate for gradings was 65.7% (322/490) and the reliability (Lin's correlation coefficient) was 0.73. In 2.2% of scans (11/490) there was a difference in classification of 2 and in only 0.2% (1/490) was there a difference of 3. When classified into 2 groups as 'severe' vs 'no/mild/moderate'. The agreement rate was 94.1% (461/490) with a kappa of 0.75. CONCLUSIONS: This study showed that an automated system can "learn" to grade central LSS with excellent performance against the reference standard. Thus SpineNet offers potential to grade LSS in large-scale epidemiological studies involving a high volume of MRI spine data with a high level of consistency and objectivity.

Positive toxicology and reactive serology in tissue donors: a retrospective study over a 3-year period.

Assessment of donor suitability and criteria development for tissue donation evaluation which appropriately addresses the risk factors for disease transmission, especially high risk for Hepatitis B or C, HIV or other transmissible diseases as defined by the Food and Drug Administration, FDA, is a continuing concern for tissue banks. The relationship of drug use, especially IV drugs, has been determined to be associated with an increased possibility of reactive serology (Centers for Disease Control and Prevention (USCDC) in Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. Hepatitis C questions and answers for health professionals. https://www.cdc.gov/hepatitis/hcv/hcvfaq.htm ; Centers for Disease Control and Prevention (USCDC) in infectious diseases, opioids and injection drug use, 2018. https://www.cdc.gov/pwid/opioid-use.html ; HIH National Institute on Drug Abuse in Health Consequences of Drug Misuse, 2017. https://www.drugabuse.gov/related-topics/health-consequences-drug-misuse ). Therefore, prior drug use determined by medical social history screening frequently results in deferral of a potential donor even when the route of drug administration has not been determined to be intravenous. Because of the association of drug use in numerous cases, which come under Medical Examiner jurisdiction, a possible rule out of a number of otherwise suitable medical examiner cases could occur. This retrospective review of medical examiner cases, tissue bank referrals and tissue donors in a 3-year period examines the relationship, if any, between reactive serology and positive toxicology results. These results would appear to indicate assessment of donor medical social history screening is effective in reducing recovery of high-risk donors.

Leptin and the intervertebral disc: a biochemical link exists between obesity, intervertebral disc degeneration and low back pain-an in vitro study in a bovine model.

PURPOSE: The aim of this study was to identify the effects of leptin upon the intervertebral disc (IVD) and to determine whether these responses are potentiated within an environment of existing degeneration. Obesity is a significant risk factor for low back pain (LBP) and IVD degeneration. Adipokines, such as leptin, are novel cytokines produced primarily by adipose tissue and have been implicated in degradative and inflammatory processes. Obese individuals are known to have higher concentrations of serum leptin, and IVD cells express leptin receptors. We hypothesise that adipokines, such as leptin, mediate a biochemical link between obesity, IVD degeneration and LBP. METHODS: The bovine intervertebral disc was used as a model system to investigate the biochemical effects of obesity, mediated by leptin, upon the intervertebral disc. Freshly isolated cells, embedded in 3D alginate beads, were subsequently cultured under varying concentrations of leptin, alone or together with the pro-inflammatory cytokines TNF-α, IL-1ß or IL-6. Responses in relation to production of nitric oxide, lactate, glycosaminoglycans and expression of anabolic and catabolic genes were analysed. RESULTS: Leptin influenced the cellular metabolism leading particularly to greater production of proteases and NO. Addition of leptin to an inflammatory environment demonstrated a marked deleterious synergistic effect with greater production of NO, MMPs and potentiation of pro-inflammatory cytokine production. CONCLUSIONS: Leptin can initiate processes involved in IVD degeneration. This effect is potentiated in an environment of existing degeneration and inflammation. Hence, a biochemical mechanism may underlie the link between obesity, intervertebral disc degeneration and low back pain. These slides can be retrieved under Electronic Supplementary Material.

ISSLS PRIZE IN BIOENGINEERING SCIENCE 2017: Automation of reading of radiological features from magnetic resonance images (MRIs) of the lumbar spine without human intervention is comparable with an expert radiologist.

STUDY DESIGN: Investigation of the automation of radiological features from magnetic resonance images (MRIs) of the lumbar spine. OBJECTIVE: To automate the process of grading lumbar intervertebral discs and vertebral bodies from MRIs. MR imaging is the most common imaging technique used in investigating low back pain (LBP). Various features of degradation, based on MRIs, are commonly recorded and graded, e.g., Modic change and Pfirrmann grading of intervertebral discs. Consistent scoring and grading is important for developing robust clinical systems and research. Automation facilitates this consistency and reduces the time of radiological analysis considerably and hence the expense. METHODS: 12,018 intervertebral discs, from 2009 patients, were graded by a radiologist and were then used to train: (1) a system to detect and label vertebrae and discs in a given scan, and (2) a convolutional neural network (CNN) model that predicts several radiological gradings. The performance of the model, in terms of class average accuracy, was compared with the intra-observer class average accuracy of the radiologist. RESULTS: The detection system achieved 95.6% accuracy in terms of disc detection and labeling. The model is able to produce predictions of multiple pathological gradings that consistently matched those of the radiologist. The model identifies 'Evidence Hotspots' that are the voxels that most contribute to the degradation scores. CONCLUSIONS: Automation of radiological grading is now on par with human performance. The system can be beneficial in aiding clinical diagnoses in terms of objectivity of gradings and the speed of analysis. It can also draw the attention of a radiologist to regions of degradation. This objectivity and speed is an important stepping stone in the investigation of the relationship between MRIs and clinical diagnoses of back pain in large cohorts. LEVEL OF EVIDENCE: Level 3.

Disc herniations in astronauts: What causes them, and what does it tell us about herniation on earth?

PURPOSE: Recent work showed an increased risk of cervical and lumbar intervertebral disc (IVD) herniations in astronauts. The European Space Agency asked the authors to advise on the underlying pathophysiology of this increased risk, to identify predisposing factors and possible interventions and to suggest research priorities. METHODS: The authors performed a narrative literature review of the possible mechanisms, and conducted a survey within the team to prioritize research and prevention approaches. RESULTS AND CONCLUSIONS: Based on literature review the most likely cause for lumbar IVD herniations was concluded to be swelling of the IVD in the unloaded condition during spaceflight. For the cervical IVDs, the knowledge base is too limited to postulate a likely mechanism or recommend approaches for prevention. Basic research on the impact of (un)loading on the cervical IVD and translational research is needed. The highest priority prevention approach for the lumbar spine was post-flight care avoiding activities involving spinal flexion, followed by passive spinal loading in spaceflight and exercises to reduce IVD hyper-hydration post-flight.

Aarhus Regenerative Orthopaedics Symposium (AROS).

The combination of modern interventional and preventive medicine has led to an epidemic of ageing. While this phenomenon is a positive consequence of an improved lifestyle and achievements in a society, the longer life expectancy is often accompanied by decline in quality of life due to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem.

Deficiency in the α1 subunit of Na+/K+-ATPase enhances the anti-proliferative effect of high osmolality in nucleus pulposus intervertebral disc cells.

Intervertebral disc cells are constantly exposed to a hyperosmotic environment. Among cellular responses towards this stress is the inhibition of proliferation through the activation of p38 MAPK and p53. In an effort to further elucidate the biochemical pathways triggered by hyperosmotic stress, we assessed the high osmolality-induced transcriptional changes of bovine nucleus pulposus cells using whole-genome arrays. A 5- and a 24-h hyperosmotic treatment led to the differential expression of >100 and >200 genes, respectively, including nine genes encoding transporters (SLC4A11, SLC5A3, ATP1A1, SLC38A2, KCNK17, KCTD20, KCTD11, SLC7A5, and CLCA2). Differences in the transcriptional profile of these selected genes, as indicated by the microarrays experiments, were validated by qRT-PCR in 2D and 3D cell cultures, under hyperosmolar salt and sorbitol conditions, revealing the presence of a common triggering signal for osmotic adaptation. The key signaling molecules p38 MAPK and p53 were demonstrated to differently participate in the regulation of the aforementioned transporters. Finally, siRNA-mediated knocking-down of each one of the three transporters with the highest and sustained over-expression (i.e., SLC4A11, SLC5A3, and ATP1A1) had a distinct outcome on the transcriptional profile of the other transporters, on p38 MAPK and p53 phosphorylation and consequently on cell cycle progression. The inhibition of ATP1A1 had the most prominent effect on the transcription of the rest of the transporters and was found to enhance the anti-proliferative effect of hyperosmotic conditions through an increased G2/M cell cycle block, ascribing to this pump a central role in the osmoregulatory response of nucleus pulposus cells.

Disc cell therapies: critical issues.

BACKGROUND: Disc cell therapies, in which cells are injected into the degenerate disc in order to regenerate the matrix and restore function, appear to be an attractive, minimally invasive method of treatment. Interest in this area has stimulated research into disc cell biology in particular. However, other important issues, some of which are discussed here, need to be considered if cell-based therapies are to be brought to the clinic. PURPOSE: Firstly, a question which is barely addressed in the literature, is how to identify patients with 'degenerative disc disease' who would benefit from cell therapy. Pain not disc degeneration is the symptom which drives patients to the clinic. Even though there are associations between back pain and disc degeneration, many people with even severely degenerate discs, with herniated discs or with spinal stenosis, are pain-free. It is not possible using currently available techniques to identify whether disc repair or regeneration would remove symptoms or prevent symptoms from occurring in future. Moreover, the repair process in human discs is very slow (years) because of the low cell density which can be supported nutritionally even in healthy human discs. If repair is necessary for relief of symptoms, questions regarding quality of life and rehabilitation during this long process need consideration. Also, some serious technical issues remain. Finding appropriate cell sources and scaffolds have received most attention, but these are not the only issues determining the feasibility of the procedure. There are questions regarding the safety of implanting cells by injection through the annulus whether the nutrient supply to the disc is sufficient to support implanted cells and whether, if cells are able to survive, conditions in a degenerate human disc will allow them to repair the damaged tissue. CONCLUSIONS: If cell therapy for treatment of disc-related disorders is to enter the clinic as a routine treatment, investigations must examine the questions related to patient selection and the feasibility of achieving the desired repair in an acceptable time frame. Few diagnostic tests that examine whether cell therapies are likely to succeed are available at present, but definite exclusion criteria would be evidence of major disc fissures, or disturbance of nutrient pathways as measured by post-contrast MRI.

Cell sources for nucleus pulposus regeneration.

PURPOSE: There is increasing interest in the development of cell therapy as a possible approach for the treatment of degenerative disc disease. To regenerate nucleus pulposus tissue, the cells must produce an appropriate proteoglycan-rich matrix, as this is essential for the functioning of the intervertebral disc. The natural environment within the disc is very challenging to implanted cells, particularly if they have been subcultured in normal laboratory conditions. The purpose of this work is to discuss parameters relevant to translating different proposed cell therapies of IVD into clinical use. RESULTS: Several sources of cells have been proposed, including nucleus pulposus cells, chondrocytes and mesenchymal stem cells derived from bone marrow or adipose tissue. There are some clinical trials and reports of attempts to regenerate nucleus pulposus utilising either autologous or allogenic cells. While the published results of clinical applications of these cell therapies do not indicate any safety issues, additional evidence will be needed to prove their long-term efficacy. CONCLUSION: This article discusses parameters relevant for successful translation of research on different cell sources into clinically applicable cell therapies: the influence of the intervertebral disc microenvironment on the cell phenotype, issues associated with cell culture and technical preparation of cell products, as well as discussing current regulatory requirements. There are advantages and disadvantages of each proposed cell type, but no strong evidence to favour any one particular cell source at the moment.

Immunolocalisation of fibrillin microfibrils in the calf metacarpal and vertebral growth plate.

Overgrowth of limbs and spinal deformities are typical clinical manifestations of Marfan syndrome (MFS) and congenital contractural arachnodactyly (CCA), caused by mutations of the genes encoding fibrillin-1 (FBN1) and fibrillin-2 (FBN2), respectively. FBN1 mutations are also associated with acromicric (AD) and geleophysic dysplasias (GD), and with Weill-Marchesani syndrome (WMS), which is characterised by short stature. The mechanisms leading to such abnormal skeletal growth and the involvement of the fibrillins are not understood. Postnatal longitudinal bone growth mainly occurs in the epiphyseal growth plate. Here we investigated the organisation of fibrillin microfibrils in the growth plate of the long bone and vertebra immunohistochemically. Fibrillin-1 was dual-immunostained with elastin, with fibrillin-2 or with collagen X. We report that fibrillin microfibrils are distributed throughout all regions of the growth plate, and that fibrillin-1 and fibrillin-2 were differentially organised. Fibrillin-1 was more abundant in the extracellular matrix of the resting and proliferative zones of the growth plate than in the hypertrophic zone. More fibrillin-2 was found in the calcified region than in the other regions. No elastin fibres were observed in either the proliferative or hypertrophic zones. This study indicates that, as fibrillin microfibrils are involved in growth factor binding and may play a mechanical role, they could be directly involved in regulating bone growth. Hence, mutations of the fibrillins could affect their functional role in growth and lead to the growth disorders seen in patients with MFS, CCA, AD, GD and WMS.

Elastic fibres are broadly distributed in tendon and highly localized around tenocytes.

Elastic fibres have the unique ability to withstand large deformations and are found in numerous tissues, but their organization and structure have not been well defined in tendon. The objective of this study was to characterize the organization of elastic fibres in tendon to understand their function. Immunohistochemistry was used to visualize elastic fibres in bovine flexor tendon with fibrillin-1, fibrillin-2 and elastin antibodies. Elastic fibres were broadly distributed throughout tendon, and highly localized longitudinally around groups of cells and transversely between collagen fascicles. The close interaction of elastic fibres and cells suggests that elastic fibres are part of the pericellular matrix and therefore affect the mechanical environment of tenocytes. Fibres present between fascicles are likely part of the endotenon sheath, which enhances sliding between adjacent collagen bundles. These results demonstrate that elastic fibres are highly localized in tendon and may play an important role in cellular function and contribute to the tissue mechanics of the endotenon sheath.

Factors regulating viable cell density in the intervertebral disc: blood supply in relation to disc height.

The intervertebral disc is an avascular tissue, maintained by a small population of cells that obtain nutrients mainly by diffusion from capillaries at the disc-vertebral body interface. Loss of this nutrient supply is thought to lead to disc degeneration, but how nutrient supply influences viable cell density is unclear. We investigated two factors that influence nutrient delivery to disc cells and hence cell viability: disc height and blood supply. We used bovine caudal discs as our model as these show a gradation in disc height. We found that although disc height varied twofold from the largest to the smallest disc studied, it had no significant effect on cell density, unlike the situation found in articular cartilage. The density of blood vessels supplying the discs was markedly greater for the largest disc than the smallest disc, as was the density of pores allowing capillary penetration through the bony endplate. Results indicate that changes in blood vessels in the vertebral bodies supplying the disc, as well as changes in endplate architecture appear to influence density of cells in intervertebral discs.

A needle micro-osmometer for determination of glycosaminoglycan concentration in excised nucleus pulposus tissue.

PURPOSE: Aggrecan is one of the major macromolecular components of the intervertebral disc (IVD) and its loss is an early sign of degeneration. Restoration of aggrecan, and hence of biomechanical properties, is a major objective of biological therapies. At present, assessment of aggrecan concentration via its glycosaminoglycan (GAG) content is accomplished using biochemical and histological methods which require sacrifice of tissue. A minimally invasive method for assessing GAG, and hence aggrecan, which can avoid destruction of tissue, would be of benefit. METHODS: We have developed a needle micro-osmometer that is capable of measuring flux of saline into excised human nucleus pulposus (NP) tissue. Using the isotropic osmotic stress technique to assess the swelling pressure of the excised NP tissue and assuming negligible collagen tensile stress, we were able to relate the flux to the tissue fixed charge density (FCD). GAG concentration is evaluated from its FCD via the radioactive tracer technique. Samples representing different ages (28-59 years) and degeneration grades (1-4) were analyzed. RESULTS: The flux is controlled by both the osmotic pressure difference across the probe's semi-permeable membrane and by the tissue permeability. A linear correlation was found between flux and the tissue FCD. The equation describing the linear fit is FCD/(total tissue hydration) = 1.97 × 10(-4) + 8283 × flux (R = 0.836, p < 10(-4)). Thus, by measuring saline flux, the concentration of GAG can be determined. CONCLUSIONS: Micro-osmometry provides a reliable and minimally invasive tool for assessing GAG content in excised NP tissue. This method may be usefully applied in tissue engineering applications. It may also be useful for in vivo measurements if the question of the degenerative effect of needle puncture can be overcome.

The distribution of fibrillin-2 and LTBP-2, and their co-localisation with fibrillin-1 in adult bovine tail disc.

We investigated the distribution of fibrillin-2 and LTBP-2 (latent TGF-ß binding protein-2) in the intervertebral disc of the adult bovine tail. The association of fibrillin-2 and of LTBP-2 with fibrillin-1 was examined by dual immunofluorescence staining. Both fibrillin-2 and LTBP-2 were found extensively distributed in all regions of the disc with the organisation of the network varying significantly region to region. In the outer annulus fibrosus (OAF) both fibrillin-2 and LTBP-2 co-localised with fibrillin-1 forming fibres running parallel to the collagen fibres of the lamellae with the microfibrillar network staining densely in between the adjacent lamellae and also at the boundaries of the collagen bundle compartments. In the inner annulus fibrosus (IAF) and nucleus pulposus (NP), co-localised fibrillin-1,2 and LTBP-2 formed a chondron-like structure around the cell. By contrast, the inter-territorial matrix of the IAF and NP contained a dense network of fibrillin-2 but only sparse/filamentous fibres of fibrillin-1 and LTBP-2. Dual immunostaining revealed that in this region, fibrillin-2 was highly colocalised with elastin. The LTBP-2 network co-localised well with that of fibrillin-1 in all regions and indeed is reported to bind strongly to fibrillin-1. However, interestingly LTBP-2 but not fibrillin-1 or fibrillin-2 was removed by hyaluronidase but not collagenase pre-digestion. Our results suggest that fibrillin-2 and LTBP-2 could play an important role in disc function.

The elastic network of articular cartilage: an immunohistochemical study of elastin fibres and microfibrils.

The elastic network of articular cartilage was investigated by immunohistochemistry using specific antibodies to elastin and fibrillin-1. Articular cartilage was dissected from defined regions of bovine metacarpophalangeal joints. Elastin fibres and microfibrils were dual-immunostained by labelling with distinct fluorescent dyes. A conventional fluorescence microscope combined with a polarized light filter was used to study the organization and degree of colocalization of elastin fibres, microfibrils and of the collagen network. We observed an elaborately organized elastic network. In the uppermost superficial zone, where few cells were present, elastin fibres and microfibrils formed a dense three dimensional network showing some degree of colocalization. The thickness and organization of this elastic network varied dramatically from region to region and was most extensive in the metacarpal palmar region. In the middle and deep zones, very few elastin fibres were observed but microfibrils formed a network in the inter-territorial matrix and dense network around the cells. Our finding of a three dimensional network of dense, well organized elastin fibres and microfibrils in the surface zone of the articular cartilage matrix, and a dense network of microfibrils around the cells deeper into the tissue suggests the elastic network could play both a mechanical and a biological role in articular cartilage.

Current perspectives on the role of biomechanical loading and genetics in development of disc degeneration and low back pain; a narrative review.

Degenerative changes in the disc have long been of interest; they are thought to be strongly associated with low back pain and caused by inappropriate loading or through injury. However, independent of the magnitude of occupational spinal loading, twin studies find that the heritability of lumbar disc degeneration is 34-74%. This finding has led to intensive searches for susceptibility genes; some genes associated with disc degeneration have been identified, though all with small effects on the degenerative process. The complex nature of degenerative changes suggests that many different genes are involved, and that interactions with environmental factors are influential in progression of degeneration. Low back pain itself also appears heritable (30-46%). The most important clinical question though, is not how discs degenerate but is disc degeneration related to low back pain. Imaging studies find many people with degenerate discs or even with discs showing pathological features such as herniations, are asymptomatic. However results are obscured by the lack of consistent definitions of the phenotypes of disc degeneration and of low back pain. Epidemiological studies could help disentangle these complex relationships, but they will only be successful once consistent classifications and phenotypes of both disc degeneration and low back pain are developed.

The elastin network: its relationship with collagen and cells in articular cartilage as visualized by multiphoton microscopy.

A combination of two-photon fluorescence (TPF), second harmonic generation (SHG) and coherent anti-Stokes Raman scattering (CARS) imaging has been used to investigate the elastin fibre network in healthy equine articular cartilage from the metacarpophalangeal joint. The elastin fibres were identified using their intrinsic two-photon fluorescence and immuno-staining was used to confirm the identity of these fibres. SHG was used to reveal the collagen matrix and the collagen fibre orientations were determined from their SHG polarization sensitivity, while CARS was used to clearly delineate the cell boundaries. Extensive elastin fibre networks were found in all the joint regions investigated. The elastin was found predominantly in the superficial zone (upper 50 microm) and was aligned parallel to the articular surface. Elastin was also detected in the pericellular matrix surrounding the superficial chondrocytes; however, individual fibres could not be resolved in this region. Variations in the density and organization of the fibres were observed in different regions on the joint surface.

The presence and absence of lymphatic vessels in the adult human intervertebral disc: relation to disc pathology.

OBJECTIVE: Although the normal adult human intervertebral disc is considered to be avascular, vascularised cellular fibrous tissue can be found in pathological conditions involving the disc such as disc herniation. Whether lymphatics vessels form a component of this reparative tissue is not known as the presence or absence of lymphatics in herniated and normal disc tissue is not known. We examined spinal tissues and discectomy specimens for the presence of lymphatics. METHODS: The examination used immunohistochemistry to identify the specific lymphatic endothelial cell markers,podoplanin and LYVE1. RESULTS: Lymphatic vessels were not found in the nucleus pulposus or annulus fibrosus of intact, non-herniated lumbar and thoracic discs but were present in the surrounding ligaments. Ingrowth of fibrous tissue was seen in 73% of herniated disc specimens of which 36% contained LYVE1+/podoplanin + lymphatic vessels. Lymphatic vessels were not seen in the sacrum and coccyx or biopsies of four sacrococcygeal chordomas, but they were noted in surrounding extra-osseous fat and fibrous tissue at the edge of the infiltrating tumour. CONCLUSION: Our findings indicate that lymphatic vessels are not present in the normal adult intervertebral disc but that, when there is extrusion of disc material into surrounding soft tissue, there is ingrowth of reparative fibrous tissue containing lymphatic vessels. Our findings also indicate that chordoma, a tumour of notochordal origin, spreads to regional lymph nodes via lymphatics in para-spinal soft tissues.