Lung nodules and bronchus sign classification: a retrospective study

A bronchus leading to a pulmonary lesion on computed tomography (bronchus sign, BS) is a known factor influencing the success of transbronchial biopsy. Imabayashi et al. recently classified BS into two groups: BS-I (reaching target lesion, including pattern Ia obstructed, Ib narrowing, Ic penetrating) and BS-II (not reaching target lesion, including pattern IIa compressed, IIb invisible, IIc uninvolved). We retrospectively analyzed bronchoscopies performed at our center over the past 3 years for lung nodules focusing on BS description and diagnostic accuracy. Procedures were conducted with the aid of radial endobronchial ultrasound and fluoroscopy, using needles and biopsy forceps. Bronchoscopy was deemed diagnostic if the samples revealed malignant or specific benign findings. Exams with nonspecific findings were considered diagnostic if follow-up imaging showed improvement or if subsequent sampling did not show malignancy. Of the 280 nodules analyzed (average diameter 19 mm, 79% solid, 85% peripheral) BS-I was present in 193 (69%) cases, primarily with an obstructed (Ia) pattern (48%). In BS-II, compressed type (IIa) was the most prevalent (52%). The overall diagnostic accuracy was 71%, with no significant difference between the two groups (p = 0.29). Our findings suggest a weak correlation between BS groups and diagnostic accuracy for lung nodules, possibly influenced by the small size and mostly peripheral location of analyzed lesions. <fig><object-id>erj;64/suppl_68/PA1624/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>