Anomalous unilateral single pulmonary vein mimicking partial anomalous pulmonary venous return.

We report a case in which the clinical findings of a partial anomalous pulmonary venous return were present but with termination of the anomalous pulmonary vein into the left atrium. There was hypoplasia of the right lung, dextroposition of the heart, and a loop-like vascular density in the right lung field. Cardiac catheterization revealed no shunt, and on pulmonary angiograms, a large common right pulmonary vein draining the entire right lung and entering the left atrium by way of a single orifice. Possible embryologic explanations include atresia of the right inferior pulmonary vein and persistence of the ipsilateral superior pulmonary vein.