A 57-year-old man underwent high-resolution computed tomography (HRCT) scanning and bronchoscopy as part of an evaluation for dyspnea and exercise intolerance. Physical examination was without abnormalities. Incidental note was made of an air-filled structure (black arrow) medial to the bronchus intermedius (BI) on HRCT (Figure 1). Bronchoscopy revealed normal airways, except for an accessory (cardiac) bronchus (ACB) arising from the BI (Figure 2).
Figure 1.
Figure 2.
ACB occur in up to 0.5% of the general population and usually end as a blind pouch. They may also be associated with small amounts of pulmonary parenchyma. ACB are almost always an incidental finding, although they may be a reservoir of infectious material, source of hemoptysis, or origin of malignancy. The most common location of ACB is the inferomedial wall of the right mainstem bronchus, but can be found arising from the BI as seen in this patient.
Author Disclosure: E.S.W. received more than $100,000 from the National Institutes of Health in sponsored grants for research funding.