A case of interruption of the inferior vena cava with azygos continuation accompanied by anomalies of tracheobronchial branching

A 31-year-old man, asymptomatic but with an abnormal shadow adjacent to the right tracheobronchial angle on chest roentogenogram, presented to our hospital. CT and MRI of the chest revealed this shadow to be a dilated azygos arch. The inferior vena cava was interrupted, at the intrahepatic portion, by the azygos continuation. There was also an abnormality of tracheobronchial branching. The right middle lobe bronchus gave rise to the upper lobe bronchus. The right B7 was absent though the left BX7 was present. The pulmonary arteries passed over the main bronchi bilaterally. Interruption of the inferior vena cava is often associated with significant cardiovascular and abdominal anomalies but only rarely with anomalies of tracheobronchial branching.