Tracheobronchopathia Osteochondroplastica

A rare benign condition in which multiple submucosal cartilaginous and bony nodules project into the lumen of the trachea and main bronchi, sparing the posterior membranous wall.

• Found in about 0.01 to 0.4% of bronchoscopies and in about 1 in 5000 autopsies; mostly men older than 50 years.
• Cause is unknown: proposed mechanisms include metaplasia of elastic tissue to cartilage and bone, chronic infection (including atrophic rhinitis from Klebsiella ozaenae), amyloid or chronic irritation, and genetic factors.
• Disease is usually slowly progressive or stable, and often an incidental finding.

Often asymptomatic.

• Symptoms: chronic cough (most common), wheeze, dyspnoea, haemoptysis, hoarseness, stridor, recurrent chest infections, difficulty with intubation or a failed extubation.
• Examination: normal, or wheeze and stridor if there is narrowing.
• Differential diagnosis: relapsing polychondritis, tracheobronchial amyloidosis, granulomatosis with polyangiitis, tracheal calcification (ageing), sarcoidosis, papillomatosis, endobronchial tuberculosis, lymphoma, tracheal tumour, chronic bronchitis, asthma.
• Complications: airway narrowing, recurrent infection, atelectasis, bronchiectasis, haemoptysis, difficult airway management, respiratory failure (rare).

Bronchoscopy (the diagnostic test): multiple hard, white, nodular or "cobblestone" projections (3 to 8 mm) in the lower two thirds of the trachea and main bronchi, with a normal posterior membrane; the larynx is usually spared.

• High-resolution CT: multiple calcified submucosal nodules of the anterior and lateral tracheal wall, with sparing of the posterior wall; with thickened but not collapsing airway.
• Spirometry and flow-volume loop: normal or reduced peak flow and flattening of the loops with significant narrowing.
• Biopsy of nodules shows cartilage and bone with haematopoietic marrow in the submucosa; it is hard to obtain and may bleed.
• Tests to exclude other causes: ESR, C-reactive protein, antineutrophil cytoplasmic antibody, angiotensin converting enzyme, serum protein electrophoresis, Congo red staining of biopsies for amyloid, mycobacterial cultures.

Asymptomatic or mild disease: observation, explanation, and avoidance of smoking.

• Symptom control:
  • Inhaled corticosteroid budesonide 400 micrograms twice daily (evidence limited) with salbutamol 100 micrograms as needed for wheeze.
  • Cough suppressant: codeine linctus 15 mg every 6 hours or dextromethorphan 15 mg every 6 to 8 hours as needed.
  • Hypertonic saline 3% 4 mL nebulised twice daily and chest physiotherapy for retained secretions.
• Treat infection promptly: amoxicillin-clavulanate 625 mg three times daily for 7 days (doxycycline 200 mg then 100 mg daily if penicillin allergic), based on sputum culture.
• Bronchoscopic treatment for symptomatic stenosis, bleeding or retained secretions: rigid bronchoscopic mechanical debulking, laser or argon plasma coagulation, cryotherapy, and balloon dilatation; silicone stent for significant stenosis (complications include migration and granulation); results are variable and the nodules can recur.
• Surgical options: tracheal resection with end-to-end anastomosis for localised disease with severe stenosis; tracheostomy bypassing the stenotic segment; both are rarely needed.
• Airway management and anaesthesia: expect difficult intubation; use a smaller tube, fibreoptic guidance and avoid trauma to the nodules; have rigid bronchoscopy available.
• Special groups: children (very rare, assess for other causes); pregnancy (observe, treat infection with amoxicillin 500 mg three times daily, plan anaesthesia carefully); elderly (most patients are older, conservative care); renal impairment (no changes); immunosuppression (exclude tuberculosis).
• Red flags: stridor, haemoptysis, recurrent pneumonia, lobar collapse, progressive breathlessness, failed intubation.
• Follow-up: clinical review and spirometry with flow-volume loop every 6 to 12 months; repeat CT or bronchoscopy for new symptoms; review after stent placement at 4 to 6 weeks and every 3 to 6 months.