Abstract Rationale Bronchoscopy is a valuable tool for diagnosing pulmonary non-tuberculous mycobacterial disease (NTM-PD) if sputum cannot be collected. In cases of nodular lesions, lung biopsy using endobronchial ultrasound with a guide sheath (EBUS-GS) is performed to differentiate NTM-PD from malignant tumors. Intraoperatively, transbronchial lung biopsy (TBLB) specimens may be collected along with instrument washing fluid. However, whether mycobacterial culture testing of TBLB specimens obtained using EBUS-GS provides additional diagnostic benefits remains unclear. This study compared the results of mycobacterial culture results from instrument washings and TBLB specimens obtained during EBUS-GS-guided TBLB in cases of suspected NTM-PD to evaluate the diagnostic significance of adding TBLB specimens. Methods This single-center, retrospective cohort study included consecutive patients who were clinically suspected of having NTM-PD and underwent TBLB using EBUS-GS at the Kameda Medical Center between April 2022 and May 2025. Cases in which culture tests for either the instrument washing fluid or TBLB specimens were not submitted and those that had already received treatment for NTM-PD were excluded. Patient enrollment was conducted during procedure scheduling, and the patients were clinically observed for six months until a diagnosis was established. Patients were grouped based on the mycobacterial culture results from TBLB specimens and instrument washing fluid, and a 2 × 2 contingency table was constructed. Results This study included 39 patients (mean age; 70 years, 24 61.5% women). Mycobacterial culture test results were positive in 11 patients (28%); among which, three (8%) were positive only on the instrument washing fluid culture, six (15%) on the instrument washing fluid and TBLB specimen cultures, and two (5%) only on the TBLB specimen culture. Conclusions For patients suspected of having NTM-PD undergoing TBLB with EBUS-GS, performing mycobacterial culture of TBLB specimens, besides instrument washing fluid culture, increased the positivity rate of the mycobacterial culture tests. Since performing one or two additional TBLB samples for culture poses minimal additional invasiveness, submitting tissue specimens for mycobacterial culture should be actively considered if NTM is suspected during EBUS-GS. This abstract is funded by: None
Yamamoto et al. (Fri,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: