Persisting unilateral lung hypoperfusion after resection of a subcarinal bronchogenic cyst.

As a rare malformation with a wide variety of clinical modes of presentation, the bronchogenic cyst remains a diagnostic challenge. We report a case with a subcarinal bronchogenic cyst and stenosis of the left main bronchus presenting as "unilateral hyperlucent lung". Hypoplasia of the ipsilateral pulmonary vascular system persisted after surgical restitution of ventilation and is most likely due to an associated vascular malformation. Alternatively, anatomical fixation of pulmonary reflex vasoconstriction can be discussed.