Partial Anomalous Pulmonary Venous Return to Azygos Vein With Absent Segmental Bronchus

Abstract

Fig 2. Apulmonary venous blood flowing directly into the right side of the heart or into the systemic veins, which creates a left-to-right shunt. The clinical importance of this anomaly is based on its association with a sinus venosus atrial septal defect in 90% of patients [1]. However, when partial anomalous pulmonary venous return is into the azygos vein, the association with pulmonary anomaly has more importance. A 51-year-old woman presented with persistent cough and recurrent right upper lobe pulmonary infections. Chest computed tomography demonstrated a mass in the posterior segment of the right upper lobe with postobstructive characteristics (Fig 1A) and suggested right upper lobe pulmonary venous drainage into the azygos vein (Fig 1B; arrow). Bronchoscopy was performed, which demonstrated an absence of the posterior segment from the right upper lobe bronchus. Transthoracic echocardiography was performed to exclude the presence of associated atrial septal defect, and results were normal. Because of the recurrent infections, thoracoscopic right upper lobectomy was recommended and performed. Posterior dissection to encircle the right upper lobe bronchus confirmed absence of the posterior segment bronchus. Anterior dissection demonstrated a single 1-mm pulmonary vein from the anterior segment draining into the superior pulmonary vein, with a large anomalous pulmonary vein draining superiorly into the azygos vein (Fig 2; AV 1⁄4 azygos vein; PA 1⁄4 pulmonary artery; SPV 1⁄4 superior pulmonary vein; SVC 1⁄4 superior