Sarasa presented a case of a young woman with recently diagnosed pulmonary TB on HREZ presenting with worsening dyspnea and voice changes. Her fiberoptic endoscopy of the upper airway was normal. She was found on CT to have tissue thickening and stranding in the mid/lower trachea as well as a small tracheal diverticula, very suspicious for endobronchial TB!

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Endobronchial tuberculosis

Definition: TB that involves the tracheobronchial tree

Epidemiology

• More common among patients with extensive pulmonary TB, especially with cavitary lesions, can occur in 10-40% of patients but less common now with anti-TB therapy.
• For some reason more likely to occur in women in second to third decades of life.
• Usually seen in main and upper bronchi, but in 5 % of cases: involves the lower trachea

Pathophysiology

• Unclear but thought to be by either direct extension of pulmonary disease into the bronchi, spread via infected sputum, or hematogenous/lymphatic spread.

Presentation:

• Cough, CP, hemoptysis, wheezing (low pitch), fatigue, fever, dyspnea. Can mimic foreign body aspiration, non-resolving pneumonia, or malignancy.
• Can have significant sputum production, leading to bronchorrhea (> 500mL/day of sputum)
• Complications: Atelectasis, obstruction, bronchiectasis, tracheal stenosis, fistula, hilar lymph node rupture

Diagnosis: CT and bronchoscopy are methods of choice for dx, with bronch being the most validated for confirming the diagnosis.

• XR: Can be normal in 10-20% of cases
• CT: Can demonstrate endobronchial lesions, stenosis (up to 2/3 of patients), or fistulas.
• Bronchoscopy: able to visualize stenosis and biopsy. Can interview if severe symptomatic stenosis.

Management

• Same as for other forms of TB but also prevent tracheobronchial stenosis
• Medical Therapy
  • Intensive Phase: HREZ (aka RIPE) x 2 months
    • R: Rifampin
    • I: Isoniazid
    • P: Pyrazinamide
    • E: Ethambutol
  • Continuation Phase
  • Ex: 2HREZ/4HR = standard regimen, 2 months of HREZ (RIPE), followed by 4 months of isoniazid and Rifampin
• Specific for endobronchial TB
  • Corticosteroids: Controversial.
    • Shown improvement in outcome (prevention of bronchial compression) in children.
    • Some data on shortening healing time and decrease severity of bronchial stenosis
  • Nebulized INH or streptomycin, mixed data
  • Surgery: Usually indicated for stenosis or stricture. Balloon dilatation, stenting, ablation, resection, cryosurgery.
  • Severe tracheobronchial stenosis sometimes requires pneumonectomy or lobectomy

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Laryngeal TB:

Distinctive entity, also more prevalence in younger patients, most commonly presents with dysphonia (96%), odynophagia (25%), and stridor (9%). True vocal cords, epiglottis, and false vocal cords are most commonly involved.

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Drug Resistance and TB

Definition:

• Drug-resistance TB: resistant to one or more anti-TB drugs
• Mono-resistant: single agent
• Poly-resistant: resistant to multiple drugs, but susceptible to either INH or rifampin but not both
• MDR: R to INH and rifampin + others.
• XDR-TB: Extensively drug resistant TB: resistant to INH, rifampin, fluoroquinolones + either aminoglycosides or capreomycin or both.

1^st Line Agents

• Rifampin
• Isoniazid
• Pyrazinamide
• Ethambutol
• Streptomycin

2^nd Line Agents

• Fluoroquinolones (Levofloxacin, Moxifloxacin)
• Injectable: Amikacin, Capromycin, Kanamycin
• Other: Cycloserine, Linezolid, Ethionamide

Addon Agents/Tertiary

Bedaquiline, Para-aminosalicyclic acid, imipenem, meropenem + Augmentin, thioacetazone.

If suspecting resistant, strategy usually is to add at least 2 additional drugs. Adding single drug inc risk for resistance.

Management of drug-resistant TB:

Tx of MTB PCR will be based on susceptibility data

• Conventional: 20-26 months treatment, with an intensive phase with at least 5 effective drugs for at least 6 months after negative sputum, followed by a continuation phase of at least 4 drugs for 18-24 months
• Shorten version for 9-12 months if no extra-pulmonary manifestation and susceptible to quinolones.

Please refer to this informative article on a review of endobronchial TB.