A medicolegal perspective on spinal tumours

Spinal tumours are relatively rare, occurring at a rate of only 0.74 to 1.6 cases per 100,000 people per year. However, the consequences can be devastating: many patients develop significant functional limitations and quality of life can be severely diminished. Spinal tumours are divided into two main types: primary tumours arise directly from the central nervous system, whereas secondary lesions, also known as metastatic tumours, spread from tumours in other areas of the body, predominately the lung, breast, kidney, prostate and thyroid. Secondary tumours are more common and make up about 85% of all spinal tumours. While primary tumours are usually found in the intradural and intramedullary spaces, secondary tumours are typically extradural, and often in bone. Spinal tumours are particularly uncommon in children and can be difficult to recognise, as they have specific features which distinguish them from lesions found in adults. Therefore, a high level of suspicion is required for early diagnosis and treatment.

Although post-mortem studies have shown that the most frequent location of vertebral secondary tumours is in the lumbar spine, diagnosis is most often made in the thoracic region. As many tumours grow insidiously at first, and the initial clinical presentation can be nonspecific, diagnosis is often missed, meaning that appropriate treatment can be delayed considerably. Magnetic resonance imaging early in the disease course is vital for accurate diagnosis and timely intervention. Once a tumour has been detected, the entire spine should be scanned to identify further lesions.

The neurological dysfunction associated with spinal tumours is usually due to compression of the spinal cord, plexopathy or radiculopathy, resulting in a loss of neuronal pathways below the level of the lesion. This compression often initially manifests as pain, which fluctuates to begin with but gradually becomes more constant. It may present several months before neurological symptoms become apparent and is caused by bony destruction, spinal cord compression, vertebral instability or spinal nerve root impingement due to vertebral lesions. The type and severity of the clinical manifestations are dependent on the degree of spinal cord involvement and the specific cord segments affected. In addition to spinal symptoms, a minority of patients also develop hydrocephalus.

The management of spinal tumours is dependent on the stability of the spine, the neurological status of the patient, deformity, and the level of pain experienced. The main treatment options are surgery, radiotherapy and chemotherapy. When possible, surgical resection of the tumour is recommended and improves median survival rates by 6 months or more. Indications for surgery include worsening neurology, spinal instability, deformity, pain or for curative resection. Short-duration radiation therapy can be given as an adjuvant therapy, commencing as soon as possible post-surgery. The main aims of surgical management are to preserve neurological function and reduce pain, while keeping intervention to a minimum to avoid other medical complications. Surgery offers the best chance of maintaining ambulatory status in patients with good function prior to intervention. These patients typically experience less pain too.

Adverse events arising from surgery include respiratory complications, deep venous thrombosis, pulmonary embolism, cerebrospinal fluid leak and wound infection or dehiscence, which is more common after radiation therapy. Myelopathy is a rare side effect of radiation therapy, which can present acutely within 4-6 months of treatment, or may be delayed by up to 2 years. Symptoms include problems with gait, or balance, coordination, and progressive weakness. Complete spinal cord injury, with loss of sphincter control, may also occur. The acute form of myelopathy can resolve within a few months, whereas the delayed form can be progressive and potentially chronic.

Chemotherapy may also be used as an adjuvant therapy for secondary spinal tumours, as well as in the treatment of some primary tumours. Corticosteroids can be included in chemotherapy regimens to decrease oxidation injury and ischemic oedema of the central nervous system. These are prescribed at high doses which are then tapered over a prolonged period. However, there is significant variability in both the initial dose and tapering schedule. Side effects of high-dose steroids include hyperglycaemia, increased risk of infections, gastrointestinal irritation, mood disorder, fluid retention and impaired wound healing. Proximal muscle weakness which develops within a few days of steroid initiation may indicate steroid-induced myopathy. It is therefore important to balance the risk of adverse effects with the benefits in terms of the control of pain and oedema before steroid therapy commences.

The pain associated with spinal tumours can be treated with bracing for body stability, medications and modalities such as heat, cold, ultrasound and electrical stimulation. While treatments that promote increased blood flow may also increase the potential for metastatic disease spread, the benefits of pain relief may outweigh this risk, particularly in advanced disease which has already spread by other means. Pharmacological interventions should be chosen on the basis of their side effect profile, the patient’s diagnosis and functional status. Rehabilitation has positive effects, even in patients with malignant tumours, many of whom are able to return home. As survival from spinal tumours improves, even small increments in function can significantly impact quality of life.