This 19-year-old female patient with no previous medical history presented to A & E with shortness of breath. Under the care of the respiratory physicians, she underwent investigations, including pleural biopsy, with no specific diagnosis ascertained.
She continued to have pyrexia of perceived unknown origin, therefore CT was performed.
Chest X-ray (CXR) on presentation demonstrated a large pleural effusion. No mediastinal lymphadenopathy (Figure 1).
Plain films of the thoracic spine showed very subtle end plate changes at T9-T10 suggestive of a possible disc centred pathology (Figure 2).
Contrast enhanced CT of the chest identified a left sided basal pleural effusion with thickened enhancing pleura (Figure 3). The CT also elucidated bony endplate destruction at T9/T10, prompting the recommendation for an MRI of the spine.
MRI of the whole spine was performed, including sequences following gadolinium.
This showed abnormal signal within the T8, T9, T10 and L4 vertebral bodies, along with high signal within the T9/T10 disc space with adjacent bony endplate destruction (Figure 4).
Following gadolinium the T8, T9, T10 and L4 vertebral bodies avidly enhance, along with a large paravertebral abscess, including in the prevertebral space, stretching the anterior longitudinal ligament (Figure 5).
Mycobacterium tuberculosis infection has increased in prevalence in recent years, typically in Asia and Africa, but also in developed countries, such as the UK. Typically mycobacterium tuberculosis is confined to the respiratory system. However, it is not uncommon for it to involve other sites, including the musculoskeletal system, in which it affects approximately 3% of infected patients [1, 3, 6].
TB spondylodiscitis is a tuberculous infection of the spine, typically the lower thoracic and upper lumbar (Pott's disease) and is the most common site of tuberculous osseous involvement [6]. Haematogenous spread of the bacillus is the cornerstone of pathogenesis. The infection starts as a spondylitis, involving the anterior endplates which contain complexes of end arterioles in which the bacilli become entrapped. It then spreads secondarily to the intervertebral disc, and then potentially beyond to the paravertebral tissues [7].
Typical clinical symptoms at presentation include; progressive back pain, local tenderness, night sweats, weight loss and fever [3, 5]. Physical examination and routine laboratory investigations may be relatively normal, making it more challenging to make an early correct diagnosis.
If not diagnosed early this disease often develops into serious complications, including kyphotic deformity. The most severe complications are; paraplegia, tetraplegia, hemiplegia or monoplegia. This may be caused by mechanical pressure on the spinal cord by an abscess, granulation tissue, tubercular debris and caseous tissue, or by mechanical instability secondary to subluxation or dislocation [4]. However, if diagnosed early, these can be prevented by treatment with anti-tuberculous medications.
The premier imaging modaility is MRI [6]. Plain X-rays are poor at detecting early changes of spinal TB. Typically infection starts at the anterior aspect of the vertebral body, resulting in end-plate oedema seen as reduced signal intensity on T1-weighted and high signal intensity on T2-weighted [6]. An image guided fine needle aspiration or biopsy may be required to aid diagnosis. There are three recognised patterns of vertebral body involvement. The patterns of vertebral body involvement may be (i) para-discal, (ii) anterior or (iii) central. The most common is para-discal [6]. A number of features are more characteristic of TB rather than pyogenic spondylodiscitis, which include; anterior corner destruction, relative sparing of the intervertebral disc, multi-level involvement with skip lesions, a large paraspinal abscess, calcification and thoracic level location [7].
The take home message is - the radiologist plays an important role in making the diagnosis of spinal TB, with MRI features that differentiate it from pyogenic infection.
Tuberculous spondylodiscitis
1. Lumbar MRI findings:
• In the lower lumbar segment (especially near the junction from the lower thoracic to upper lumbar vertebrae), signal changes are noted at the anterior margin of the vertebral body, showing low signal on T1WI and high signal on T2WI.
• Evidence of endplate destruction extending into the intervertebral disc space, suggesting a vertebral-disc inflammatory process (spinal infection).
• Paravertebral/para-spinal soft tissue thickening or mass-like shadow, with some areas appearing to have fluid or abscess formation.
2. Chest imaging (including X-ray and CT) shows:
• Pleural thickening, and in some areas, increased density or fluid suggesting pleural reaction or pleural effusion.
• Enhanced thickening, with visible enhancement on contrast scans in the thickened pleural region.
• Adjacent paravertebral soft tissue also shows changes related to inflammation or infection, with local osteolytic or bone destruction visible.
Overall imaging indicates simultaneous involvement of the spine and pleura, consistent with a chronic infectious or granulomatous lesion.
1. Tuberculous spondylitis (Pott’s disease):
• Tuberculosis infection in the respiratory or skeletal system is relatively common, especially with involvement of the anterior margin of the vertebral body and the intervertebral disc, often extending along the anterior longitudinal ligament or forming paravertebral abscesses.
• Tuberculous pleural and pulmonary lesions on imaging may appear as pleural thickening or pleural effusion, often showing dense enhancement after contrast.
2. Pyogenic spondylitis (bacterial spinal infection):
• Clinically, acute inflammatory signs may occur, such as high fever and significant leukocytosis.
• Imaging often shows rapid destruction of the intervertebral disc and vertebral bodies along with a notable paravertebral abscess. In prolonged cases, it may resemble TB, requiring further pathogen identification for confirmation.
3. Uncommon causes of vertebral destruction (tumors or metastases):
• Lytic lesions of the vertebrae (e.g., lymphoma, metastatic tumors) may be considered, but they usually present with varying degrees of bone destruction and soft tissue masses, and may not necessarily involve the intervertebral discs.
• Correlating clinical history and imaging features, tuberculous infection with pleural involvement is still more likely in this scenario.
Based on imaging features — anterior vertebral body destruction involving the intervertebral disc, paravertebral abscess, pleural thickening, and pleural effusion — tuberculous spondylitis and associated tuberculous pleuritis are most consistent. Pyogenic bacterial infection or rare tumors/metastases should still be ruled out with pathogen or histopathological testing.
Considering the patient’s youth, clinical symptoms (fever, back pain, chest discomfort/shortness of breath), imaging characteristics (vertebral and disc destruction, paravertebral and pleural lesions), and other ancillary tests (e.g., positive sputum TB bacilli, tuberculin skin test, or interferon-gamma release assay), the most likely diagnosis is:
Tuberculous spondylitis (spinal tuberculosis, Pott’s disease) with pleural involvement.
1. Pharmacotherapy:
• Primarily anti-tuberculosis medications (the conventional four-drug regimen: isoniazid, rifampin, pyrazinamide, ethambutol) for at least 6–9 months, extendable if necessary.
• In the presence of significant spinal structural damage or neurological compression symptoms, close monitoring of possible spinal canal narrowing and nerve function is required.
2. Surgical Indications:
• If there is severe bony destruction, spinal cord or nerve root compression, spinal instability, or acute neurologic deterioration, consider surgical decompression, debridement, and internal fixation.
• For poorly controlled lesions or large abscess formation, interventional drainage or surgical management may be required.
3. Rehabilitation and Exercise Prescription (FITT-VP principle):
• Initial Stage (acute/infection control phase):
- Exercise types: Basic breathing exercises (thoracic and abdominal breathing) and isometric lower extremity exercises, minimizing heavy load activities.
- Frequency and Duration: 2–3 times daily, 5–10 minutes each, focusing on breathing exercises and basic muscle strengthening.
- Intensity: Low-intensity to prevent fatigue and excessive energy consumption.
- Progression: Once body temperature stabilizes and symptoms improve, gradually increase trunk strengthening and stability exercises.
• Recovery Stage:
- Exercise types: Gradually add core muscle training (pelvic lift in the supine position, bridging exercises, etc.). Under medical or rehabilitation specialist supervision, introduce mild weight-bearing or low-impact exercise like swimming.
- Frequency and Duration: 3–5 times per week, 20–30 minutes each, increasing gradually based on recovery progress.
- Intensity: Moderate intensity is recommended to maintain or recover muscle strength and cardiopulmonary function.
- Progression: According to bone healing and lesion control, appropriate progression of core stabilization, balance, and flexibility training.
• Precautions:
- If there is marked spinal instability or risk of nerve injury, exercises should be performed under the protection of a brace (lumbar or thoracolumbar support).
- Regularly review imaging and clinical indicators; if pain worsens or neurological symptoms occur, seek medical attention immediately.
Disclaimer:
The above content is based on imaging and clinical information for reference purposes only and does not replace in-person consultation or professional medical advice. Specific treatment plans should be formulated through comprehensive clinical assessment by qualified medical professionals.
Tuberculous spondylodiscitis
