Left main bronchial obstruction caused by a mediastinal bronchogenic cyst.

A 25-year-old female presented with sudden-onset dyspnoea. A chest X-ray showed total atelectasis on the left haemithorax (Fig. 1). A chest computed tomography (CT) revealed a cystic mass in the posterior mediastinum that compressed the left main bronchus (Fig. 2). Pathological examination confirmed a broncho-genic cyst in the posterior mediastinum. Figure 1: Chest X-ray showing total atelectasis on the left haemithorax. Figure 2: (A) Chest CT scan showing a mediastinal cystic mass and deviated mediastinal structures with atelectasis. (B) Coronal CT image showing compression of the left main bronchus and distal atelectasis. BC: bronchogenic cyst; E: oesophagus; white arrow: obstructed left main bronchus.