Unexpected diagnosis of pulmonary tuberculosis during bronchoscopy using radial probe endobronchial ultrasound

Background: Endobronchial ultrasound guide-sheath (EBUS-GS) is performed when a peripheral lung lesion is suspected to be malignant. However, tuberculosis is unexpectedly diagnosed. In this study, we examined the incidence and factors associated with unexpected diagnosis of tuberculosis during EBUS-GS. Methods: This retrospective study included 970 patients who received EBUS-GS between December 2015 and November 2018. Clinical, histological, radiological, and microbiological data were reviewed. Results: Pulmonary tuberculosis was unexpectedly diagnosed in 31 patients (3.2%) during EBUS-GS. Patients with a lower age were significantly more likely to be diagnosed with tuberculosis (OR, 0.95; P = 0.001). Among the computed tomography (CT) findings, a low Hounsfield Units difference between pre- and post-enhanced CT (OR, 0.97; P = 0.022), the presence of concentric cavitation (OR, 5.21; P = 0.012), and satellite centrilobular nodules (OR, 22.92; P < 0.001) were independently associated with unexpected diagnosis of tuberculosis. Conclusions: The incidence of unexpected diagnosis of tuberculosis during EBUS-GS was 3.2%. Even in patients suspected with lung cancer, healthcare workers in the bronchoscopy suite should consider high-grade respiratory precaution.