Left bronchial isomerism, normal atrial arrangement and bronchomalacia mimicking asthma: a new syndrome?

Three children who presented with steroid-resistant airflow obstruction are described. They all had bronchomalacia in the setting of a rare visceral arrangement, namely left bronchial isomerism with normal atrial arrangement. Imaging and, in two cases, a normal residual volume in the face of severe airflow obstruction were diagnostic pointers to a nonasthmatic cause of wheeze. Although the association of these abnormalities may be coincidental, together they may constitute a new clinical syndrome.