Diagnostic utility of bronchoscopy in diagnosing pulmonary infections among malignancy patients undergoing treatment: A cross-sectional study

Background: In cancer patients receiving chemotherapy or immunosuppressive treatments, lung infections significantly affect illness and death rates. Early diagnosis is crucial for targeted therapy. This study evaluated the diagnostic yield and microbiology of bronchoscopic procedures – bronchial wash (BW), protected specimen brush (PSB), bronchoalveolar lavage (BAL), and transbronchial needle aspiration (TBNA) in patients with malignancy and suspected lung infections. Methods: One hundred and twenty-five patients with solid or hematological malignancies and radiological evidence of pulmonary infection were enrolled. Patients underwent flexible video bronchoscopy with BAL and/or BW, PSB, or TBNA sampling. Specimens were processed for bacterial, fungal, and mycobacterial culture, cytological analysis, and antimicrobial susceptibility testing. Results: Of 125 patients, 104 (83.2%) had positive microbiological results. Bacterial infections were found in 65 (52%) cases, mainly Pseudomonas aeruginosa and Escherichia coli . Fungal isolates were identified in 10 (8%) cases, primarily Aspergillus spp. and Candida albicans . Mycobacterial infections were confirmed in 29 (23.2%) patients. Cytological analysis showed neutrophilic predominance in bacterial infections, lymphocytic predominance in mycobacterial infections, and mixed patterns in fungal infections. Significant associations ( P = 0.00026) existed between malignancy subtypes and infection patterns. Forty percent of bacterial pneumonia cases were linked to lung cancer, while tuberculosis/nontuberculous mycobacteria infections were associated with hematologic malignancies (15/29). Other cancers accounted for 58% of bacterial pneumonia and 71% of unconfirmed infections. Conclusion: Bronchoscopy with BAL/BW effectively diagnosed lung infections in immunocompromised patients with cancer. Integrating cytological assessments with microbiological findings enhances diagnostic accuracy, aiding appropriate empirical treatment selection. Regular antibiogram surveillance is vital for optimizing antimicrobial stewardship.