Background
Extrinsic airway compression refers to narrowing of the airway, typically by at least 50% or more of its diameter, resulting in reduced airflow to lung tissue. 1 Airway injury is a recognised complication of external airway compression apart from atelectasis, post-obstructive pneumonia and recurrent infections. 1 The causes can be further classified as benign or malignant. 1 2
Vertebral osteophytes is a common condition, especially among the elderly. They are usually asymptomatic but can cause symptoms due to mass effect on nearby structures. 3 The main structures affected are the airways, pleura, aortic arch, oesophagus and nerves (ie, sympathetic trunk and greater splanchnic nerve). 3 Airway compression from spinal pathologies is a rarely reported clinical phenomenon. The proximity of the right main bronchus to the thoracic vertebrae renders it vulnerable to compression from spinal abnormalities. 4 5 We report a rare presentation of pneumonia secondary to external compression of the right main bronchus by lower thoracic vertebral osteophytes.
Case presentation
A male in his mid-to-late 80s presented to our hospital with a week-long history of lethargy, non-specific malaise, mild confusion, postural dizziness and abrupt functional decline. He reported no localising symptoms for infection. His medical history was significant for Parkinson’s disease and hypercholesterolaemia. He is a non-smoker and had been fully independent in his activities of daily living until a couple of weeks prior to presentation. His initial vital signs revealed mild hypoxaemia but were otherwise within normal limits (saturation of peripheral oxygen (SpO2) 92% on room air, temperature of 36.5℃, heart rate of 78 beats/min, respiratory rate of 19 breaths/min, blood pressure of 134/84 mm Hg). There was a significant postural systolic blood pressure drop from 134 to 93 mm Hg. Clinical examination revealed markedly reduced air entry at the right lung base but no bronchial breathing or crackles.
Investigations and differential diagnosis
Initial laboratory investigations revealed an elevated C-reactive protein at 86 mg/L, total white cell count of 5.8×10 9 /L and renal impairment with creatinine of 122 micromol/L and estimated glomerular filtration rate (eGFR) of 45 mL/min. Microbiological investigations demonstrated negative urine microscopy and culture, negative blood cultures and no detectable viruses on respiratory viral nasopharyngeal swab ( box 1.A ). Sputum microscopy and culture were not performed as the patient was not able to expectorate sputum. Serum alkaline phosphatase was elevated at 1910 U/L with normal bilirubin and transaminases which raised the possibility of underlying bone pathology. Corrected calcium and phosphate level were within normal range while 25 hydroxy-vitamin D level was in the deficient range ( box 1.A ).
Initial basic laboratory investigations
FBC: Hb 116 g/L; WCC 5.8×10 9 /L; N 5.8×10 9 /L; platelets 189×10 9 /L
RFT: Na 134 mmol/L; K 4.8 mmol/L; urea 12.2 mmol/L; creatinine 122 umol/L; eGFR 45 mL/min
LFT: bilirubin 8 U/L; ALP 1910 U/L; ALT 48 U/L; total protein 64.7 g/L; albumin 31 g/L
Corrected calcium 2.43 mmol/L; phosphate 1.07 mmol/L; 25-OH vitamin D 22 nmol/L
CRP 86 mg/L
Respiratory viral swab*: negative
Blood cultures: (aerobic and anaerobic bottles) showed no growth
Prostate specific antigen 1112 micrograms/L (0-4)
Follow-up test
FBC: Hb 114 g/L; WCC 6.8×10 9 /L; N 5.1×10 9 /L; platelets 188×10 12 /L
RFT: Na 136 mmol/L; K 4.4 mmol/L; bicarbonate 25 mmol/L; chloride 103 mmol/L; urea 10 mmol/L; creatinine 88 micromol/L; GFR 67 mL/min
LFT: bilirubin 6 U/L; ALP 1852 U/L; ALT 29 U/L; protein 32 g/L
CRP 38 mg/L
ALP, alkaline phosphatase; ALT, alanine transaminase; CRP, C-reactive protein; FBC, full blood count; GFR, glomerular filtration rate; K, potassium; LFT, liver function test; N, neutrophils; Na, sodium; RFT, renal function test; WCC, white cell count.
*Respiratory viral panel includes for influenza A and B, human parainfluenza viruses, enterovirus, adenovirus, human metapneumovirus, Bordetella pertussis and SARS-CoV-2.
His admission chest X-ray (CXR) showed only minimal blunting of the right costophrenic angle ( figure 1 ). Given the elevated inflammatory markers , mild hypoxaemia, unexplained acute confusional state and CXR findings, the patient was treated as community acquired pneumonia with intravenous ceftriaxone and azithromycin as per Infectious Disease Society of America (IDSA) guidelines. Acute cerebrovascular insult was excluded by a normal non-contrast CT brain. A chest CT scan performed a day later identified severe compression of the right main bronchus by a very large thoracic vertebral osteophyte at T5-T6 ( figure 2 ). A right-sided pleural effusion was evident, but overt consolidation was not identified. Incidental note was made of numerous sclerotic bony lesions throughout the vertebrae. Prostate specific antigen was markedly elevated at 1112 micrograms/L ( box 1.A ). CT abdomen and pelvis confirmed marked prostatomegaly, diffuse pelvic lymphadenopathy and innumerable skeletal metastases confirming the diagnosis of metastatic prostate malignancy. A radiology second opinion was obtained regarding the findings and confirmed that osteophytes causing compression were related to vertebral osteoarthritis and not the osteolytic lesions, clearly demonstrated on sagittal slices ( figure 3 ).
Treatment
Following a 5-day course of antibiotics and chest physiotherapy, resting oxygen saturation improved to >94% on room air. Additionally, both confusion and drowsiness resolved, and his overall functional status returned to baseline. C-reactive protein and renal function also showed significant improvement (see box 1.B ).
The medical oncology team evaluated the patient and initiated antiandrogen and endocrine therapy (goserelin and bicalutamide) for advanced prostate cancer. The agreed treatment goal with the patient and family was palliative care. An initial discussion with the family considered bronchoscopy to address persistent symptoms by clearing mucus from the obstructed airway if necessary. However, given the clinical improvement with antibiotics and patient frailty, bronchoscopy was not pursued and no attempt at endobronchial stenting or spinal surgery was considered.
Outcome and follow-up
The patient continued following up with his private medical oncologist as an outpatient and agreed to continue antiandrogen therapy 3-monthly injection and endocrine therapy four weekly. Six months post-discharge, the patient was readmitted to another hospital with recurrent chest infection, accompanied by further functional and cognitive decline. A follow-up chest CT scan ( figure 4 ) demonstrated persistent bronchial narrowing and newly developed right lower lobe subsegmental atelectasis. The patient was again treated with antibiotics and kept on other supportive measures (ie, physiotherapy and nebulisers). One year following initial diagnosis, the patient’s clinical course was truncated by a fatal intracerebral haemorrhage which was considered a terminal event independent of the ongoing respiratory pathology.
Discussion
Vertebral osteophytes are common pathological findings in elderly patients, 3 4 but rarely impact on the airways. In this case, the main cause of our patient’s recurrent pneumonia is bronchial compression by lower thoracic osteophytes related to osteoarthritis. Vertebral osteophytes represent bony overgrowth resulting from fibrocartilaginous proliferation associated with osteoarthritis. 3 6 Their formation involves a neochondrogenesis process that primarily starts as a response to the desiccation of the nucleus pulposus to enhance spine stability and resilience in response to weight-bearing loads. 3 The vertebral osteophytes often occur in the lower thoracic region, frequently on the right side where they tend to be larger in size and thickness as the aorta limits their growth on the left side. 4 5 In extreme cases, compression of adjacent structures can result in functional impairment.
Airway compression from vertebral osteophytes has only very rarely been reported. One case reported chronic obstructive pneumonia secondary to right main bronchus compression by anterior vertebral osteophyte in an 85-year-old male, similar to our case; notably, the recurrent infections resolved completely after corrective spine surgery. 7 Another reported case involved recurrent pneumonia due to bronchus intermedius compression in the setting of severe scoliosis. 8 While the clinical presentation was comparable, the underlying mechanism in this case was spinal misalignment rather than osteophytes as we have described. 8 Post compression airway changes include atelectasis, collapse, subpleural changes and with or without infection. An image case report presented bronchiolectasis secondary to right-sided thoracic osteophytes. 9
We report an unusual presentation of pneumonia caused by severe right main bronchus compression by vertebral osteophyte. The presence of confusion, hypoxia, high inflammatory markers, reduced air entry on chest auscultation and subtle chest XR changes, supported a working diagnosis of community acquired pneumonia. This approach was appropriate given resolution of the acute clinical syndrome with antibiotic therapy. However, the isolated elevated ALP raised suspicion for underlying bone pathology rather than hepatobiliary causes. Considering the patient’s age, primary malignancy (such as multiple myeloma) or metastatic disease were the differentials. The subsequent chest CT played a crucial role in identifying both the bronchial compression and evidence of both severe vertebral osteophytes and thoracic bony metastases. Subsequent CT abdomen and pelvis and PSA prompted a new diagnosis of metastatic prostate malignancy. Importantly, the bronchial compression was attributable to degenerative vertebral changes rather than malignant infiltration.
Management of tracheobronchial obstructions is often complex and requires careful consideration of the underlying aetiology, severity of compression, risk of complications and patient suitability for intervention. 10 The vertebral osteophytes are generally managed conservatively, unless symptoms persisted and/or progressed or started causing functional compromise. 10 The reported treatment option for similar cases is osteophyte resection via video-assisted thoracoscopy. 7 8 Pongmanee et al reported a case of diffuse idiopathic skeletal hyperostosis-related thoracic osteophytes resulting in oesophageal compression with dysphagia and dyspepsia in which anterior osteophyte resection resulted in subsequent clinical improvement. 11 Bronchial stenting represents an alternative approach in patients who are not surgical candidates. 8 A case report described successful bronchial stenting to relieve symptomatic bronchial compression due to scoliosis in a patient for whom repeat spinal surgery was deemed anatomically challenging. 8 Bronchoscopy is often considered in such cases to assist with sputum clearance, identifying the causative organisms, exclusion of endobronchial pathologies and potential endobronchial intervention. However, outcomes following bronchial stenting for extrinsic compression are not widely reported, and significant complications, including stent migration, have not been well reported. 1 In our report, the patient’s frailty and end-stage cancer with poor prognosis have limited the consideration of these management options and opted toward palliation.
Our case report presents a rare scenario with few comparable examples in the existing literature. To improve clinical insights about different clinical presentations and management approaches, further case reports, case series or retrospective studies reporting clinical implications and considered management approaches would be helpful to guide therapeutic decision-making regarding airway compression by thoracic osteophytes. Nonetheless, our case offers valuable information that may assist clinicians and serve as an educational resource for radiologists by illustrating the direct impact of vertebral pathology on the airways.
Consent
Informed consent for the publication of this case report was initially obtained verbally and via email from the patient’s next of kin prior to the patient’s death. Following the patient’s passing and to meet formal documentation requirements, a BMJ Deceased Patient Consent Form was completed and signed by the next of kin. The next of kin has reviewed the final manuscript, is aware that the report will be published in an open-access format and has confirmed that the patient’s identity remains protected through anonymisation.
Patient’s perspective
Not done as the patient clinical and mental function were deteriorating.
Learning points
Vertebral osteophyte is a common pathology in the elderly that can in extreme cases affect nearby structures resulting in functional impairment.
Atypical presentations with non-specific laboratory results that do not fit one clinical picture should raise the suspicion of underlying pathologies prompting further investigations, especially in elderly patients.
It is highly advised that physicians dealing with the ageing population should recognise degenerative structural changes as a potential cause of acute on chronic airway obstruction.
Corrective resection of vertebral osteophytes and/or bronchial stenting are considered as options in osteophyte-related bronchial compression but may be unsuitable in elderly frail patients.
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
Provenance and peer review: Not commissioned; externally peer reviewed.
Patient consent for publication: Consent obtained from parent(s)/guardian(s).
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