A 45-year-old woman from Delhi with a known history of pulmonary TB completed anti-tuberculous therapy 6 months ago. She now presents with recurrent cough and mild dyspnea. A follow-up chest X-ray shows fibrotic streaking, volume loss, and bronchiectasis in the right upper lobe with traction bronchiectasis. There is no cavitary lesion or active consolidation. Sputum smear is negative. What is the most likely diagnosis based on these radiological findings?

Explanation

## Post-Tuberculous Sequelae: Bronchiectasis and Fibrosis **Key Point:** After successful anti-TB therapy, residual radiological changes—fibrosis, volume loss, and bronchiectasis—represent permanent structural damage rather than active disease. These findings persist even after cure and do not require anti-TB re-treatment if sputum smear is negative. ### Distinguishing Active TB from Post-TB Sequelae | Feature | Active TB | Post-TB Sequelae | |---------|-----------|------------------| | **Sputum smear** | Positive (infectious) | Negative | | **Cavitation** | Present, with surrounding consolidation | Absent or fibrosed | | **Consolidation** | Active, with ill-defined margins | Resolved; fibrotic streaking only | | **Volume loss** | Minimal | Marked (traction) | | **Bronchiectasis** | Not typical | Traction bronchiectasis common | | **Clinical course** | Progressive symptoms | Stable or slowly progressive | **High-Yield:** Fibrotic streaking, volume loss, and traction bronchiectasis in the upper lobes after completed TB therapy = **post-tuberculous sequelae**, NOT recurrent active disease. The negative sputum smear confirms non-infectivity. ### Mechanism of Post-TB Bronchiectasis 1. **Caseous necrosis and cavity formation** during active TB 2. **Healing and fibrosis** with anti-TB therapy 3. **Traction bronchiectasis** develops as fibrotic tissue contracts, pulling airways open 4. **Permanent structural damage** — airways remain dilated and damaged 5. **Secondary infections** (including non-tuberculous mycobacteria, aspergillus) may occur **Clinical Pearl:** Patients with post-TB bronchiectasis are at risk for **non-tuberculous mycobacterial (NTM) infection** and **aspergilloma** if cavities persist. However, this patient has no cavitary lesion, making aspergilloma unlikely. **Mnemonic: FVBT** — Fibrosis, Volume loss, Bronchiectasis, Traction (post-TB sequelae) ### Why Not Aspergilloma? Aspergilloma (fungal ball) develops within a **pre-existing cavity**. This patient has no cavitary lesion on imaging—only fibrotic changes. Aspergilloma would present with a mobile opacity within a cavity, often with a halo sign. [cite:Harrison 21e Ch 205]