Value of ultrasound guided biopsy combined with Xpert Mycobacterium tuberculosis/resistance to rifampin assay in the diagnosis of chest wall tuberculosis

BACKGROUND: The thoracic wall lesions, particularly chest wall tuberculosis, and chest wall tumors and other pyogenic wall and actinomycetes infections, almost always present as a diagnostic challenge. AIM: To explore the value of ultrasound-guided biopsy combined with the Xpert Mycobacterium tuberculosis/resistance to rifampin (MTB/RIF) assay to diagnose chest wall tuberculosis. METHODS: We performed a retrospective study of patients with chest wall lesions from March 2018 to March 2021. All patients received the ultrasound-guided biopsy for pathology examination, acid-fast Bacillus staining, mycobacterial culture, and Xpert MTB/RIF analysis. The sensitivity, specificity, and area under the curve (AUC) were calculated for these diagnostic tests, either individually or combined. Rifampicin resistance results were compared between the mycobacterial culture and the Xpert MTB/RIF assay. RESULTS: In 31 patients with the chest wall lesion biopsy, 22 patients were diagnosed with chest wall tuberculosis. Of them, 3, 6, and 21 patients tested positive for mycobacterial culture, acid-fast stain, and Xpert MTB/RIF assay, respectively. The rifampicin resistance results of the 3 culture-positive patients were consistent with their Xpert MTB/RIF assay results. When considering the sensitivity, specificity, and AUC value, the Xpert MTB/RIF assay (95.5%, 88.9%, and 0.92, respectively) was a better choice than the acid-fast Bacillus stain (27.3%, 100.0%, and 0.64, respectively) and mycobacterial culture (13.6%, 100.0%, 0.57, respectively). No complications were reported during the procedure. CONCLUSION: Ultrasound guided biopsy combined with Xpert MTB/RIF has high value in the diagnosis of chest wall tuberculosis, and can also detect rifampicin resistance.