Thickening of the posterior wall of the bronchus intermedius. A sign on lateral radiographs of congestive heart failure, lymph node enlargement, and neoplastic infiltration.

The posterior wall of the bronchus intermedius (PWBI) is outlined on most lateral chest radiographs by air in the lumen and in adjacent lung. In a prospective review over a 19-month interval, the authors found 36 patients whose PWBI was thick, defined as thickness greater than the normal upper limit of 3.0 mm (33 patients) or as increase of 1.5 mm in thickness compared with control radiographs (three patients). Uniform thickening was found in 23 patients as a sign of congestive heart failure. Nine subjects with neoplastic thickening of the PWBI demonstrated either uniform (six patients) or lobulated (three patients) enlargement. Two patients with sarcoidosis showed lobulated thickening of the PWBI. Inspection of lateral chest radiographs for thickening of the PWBI may be helpful in establishing bronchial involvement by edema, neoplasm, or enlarged lymph nodes.