Case Report: Pulmonary <i>Mycobacterium avium</i> complex mimicking recurrent tuberculosis in a patient with suspected pneumoconiosis and destroyed lung diagnosed by bronchoalveolar lavage fluid targeted next-generation sequencing

A 42-year-old man, a coal miner with a history of pulmonary tuberculosis, dust exposure, and suspected pneumoconiosis, presented with cough, purulent sputum, and intermittent fever for more than 1 month. Routine sputum bacterial and fungal cultures, as well as acid-fast bacilli smears, were persistently negative. Chest computed tomography revealed markedly distorted bilateral lung architecture with patchy and nodular opacities, multiple irregular cavitary lesions, emphysema, pulmonary bullae, and mediastinal lymphadenopathy. To obtain a definitive diagnosis, a bronchoscopy was safely performed under strict asepsis and painless anesthesia. The procedure showed inflammatory bronchial changes and narrowing of the right upper lobe posterior and dorsal segmental bronchi due to external compression. Targeted next-generation sequencing (tNGS) of the bronchoalveolar lavage fluid on the MGI VisionSeq 1000 platform detected Mycobacterium avium complex (349 sequence reads, 53.4% relative abundance). The patient's condition improved rapidly following a targeted multidrug regimen (clarithromycin, rifampicin, ethambutol, and amikacin) combined with supportive pneumoconiosis care. This case highlights the vital role of tNGS in differentiating nontuberculous mycobacterial disease from recurrent tuberculosis in patients with complex structural lung damage, enabling timely and precise intervention.