Two Case Reports of Drug-Resistant Tuberculous Pleurisy in Children: Thoracoscopic Pleural Biopsy and PCR-Based Drug-Resistance Testing.

Background: Drug-resistant tuberculous pleurisy is difficult to diagnose in children because pleural fluid is paucibacillary, culture is slow and frequently negative, and Xpert detects only rifampicin resistance. Case Presentation: We report two children in whom thoracoscopic pleural biopsy combined with PCR-high-resolution melting (HRM) drug-resistance testing identified drug-resistant tuberculosis. Case 1, an 8-year-old girl with tuberculous pleurisy, showed persistent pleural thickening and a new mass after two months of standard first-line therapy; pleural tissue PCR detected rpoB and inhA mutations, confirming multidrug-resistant tuberculosis (MDR-TB), and she responded to an all-oralbedaquiline- and delamanid-containing regimen. Case 2, a 9-year-old boy with loculated tuberculous pleurisy and negative cultures, had an rpoB mutation confirming rifampicin-monoresistant tuberculosis; he recovered with a rifampicin-sparing regimen and remained relapse-free at one year. Conclusion: In pediatric tuberculous pleurisy, particularly when fluid-based testing is uninformative or first-line therapy fails, thoracoscopic pleural biopsy combined with molecular drug-resistance testing of tissue is decisive for detecting occult drug-resistant tuberculosis and enabling timely, individualized treatment.