Spinal Tumours

Spinal tumours are neoplasms located in either the vertebral column or the spinal cord. They are classified into three main types based on their location: extradural, intradural-intramedullary, and intradural-extramedullary.

Extradural tumours are outside the dura mater and are most commonly metastatic.

Intradural tumours are inside the dura mater and can be either within the spinal cord parenchyma (intradural-intramedullary) or outside it (intradural-extramedullary).

The most common presenting symptom is nocturnal back pain, with other symptoms including muscle weakness, sensory loss, and difficulty walking. In later stages, loss of bowel and bladder control may occur.

Causes

The exact cause of most spinal tumours remains unknown. Extradural tumours are typically metastatic, originating from cancers such as those of the breast, prostate, lung, and kidney. Intradural tumours are often associated with genetic syndromes: neurofibromatosis 1 (NF1) is linked with neurofibromas, neurofibromatosis 2 (NF2) with meningiomas and schwannomas, and Von-Hippel Lindau (VHL) syndrome with hemangioblastomas.

Pathophysiology

The spinal cord, encased in the vertebral column, extends from the foramen magnum to the conus medullaris. Symptoms primarily arise from spinal cord compression, impacting motor and sensory functions. The spinal cord is enveloped by three meninges: dura mater, arachnoid mater, and pia mater. Tumours are classified based on their location relative to these layers.

Intradural-intramedullary tumours, such as ependymomas and astrocytomas, are located within the spinal cord. Intradural-extramedullary tumours, such as meningiomas and nerve sheath tumours (e.g., schwannomas, neurofibromas), are inside the dura but outside the spinal cord parenchyma. Extradural tumours are primarily metastatic and located outside the dura, often affecting the vertebral bodies.

Signs and Symptoms

The symptoms of spinal tumours are often non-specific, leading to diagnostic delays. Pain is the most common presenting symptom, often worsened at night. Other symptoms include muscle weakness, sensory loss, numbness in extremities, and rapid-onset paralysis. In advanced stages, bowel or bladder incontinence may occur. In children, spinal deformities like scoliosis may be observed. The diagnosis can be challenging as symptoms often mimic common degenerative spinal diseases.

Spinal cord compression is a frequent finding in metastatic malignancies. Back pain is a key symptom, especially in patients with known malignancies, prompting bone scans to confirm or exclude spinal metastasis. Rapid identification and intervention are very important to preserve neurological function.

Diagnosis

Medical Examination

Diagnosing spinal tumours is challenging due to non-specific symptoms. A thorough medical examination, including a comprehensive neurological exam, is essential to identify motor or sensory deficits. Patients with radiculopathy or myelopathy warrant further investigation.

Imaging

Imaging is very important when diagnosis is uncertain or immediate intervention is required. MRI is the preferred imaging modality, using T1-weighted, T2-weighted, and contrast-enhanced T1-weighted sequences. Short-TI Inversion Recovery (STIR) is also commonly used. Myelography may substitute MRI when the latter is unavailable. X-rays and CT scans are primarily used to assess bony structures but are less effective for spinal cord tumours. Bone scans can supplement imaging for tumours involving spinal bony structures.

Treatment

Treatment varies based on tumour type, goals of care, and prognosis. Main treatment modalities include surgery, radiotherapy, and chemotherapy. Steroids may be administered to reduce inflammation around the tumour.

Surgery

Surgical indications include tumour resection, nerve decompression, and spinal stabilisation. Total gross resection is a potential cure for primary spinal cord tumours, particularly extramedullary tumours. In metastatic cases, surgery aims to improve quality of life by alleviating pain, stabilising the spine, and decompressing the spinal cord.

Non-Surgical Treatment

Non-surgical options include observation, chemotherapy, and radiotherapy. Observation is viable for small, asymptomatic benign tumours. Chemotherapy and radiotherapy can be used alone or alongside surgery, with the choice depending on tumour type, histological grade, and surgical resection extent. Minimally invasive surgery combined with radiation or chemotherapy is an emerging technique for tailored treatment of spinal tumours.

Self-assessment MCQs (single best answer)

What is the most common presenting symptom of spinal tumours?

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Which type of spinal tumour is most commonly metastatic?

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Neurofibromatosis 2 (NF2) is associated with which type of spinal tumour?

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What imaging modality is preferred for diagnosing spinal tumours?

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Which symptom is often observed in advanced stages of spinal tumours?

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Which syndrome is associated with hemangioblastomas in the spinal cord?

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Intradural-intramedullary tumours are located:

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Which type of tumour is typically observed in patients with a history of breast, prostate, lung, or kidney cancer?

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The most appropriate first-line treatment for small, asymptomatic benign spinal tumours is:

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For which condition is total gross resection considered potentially curative?

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