LAUSR

To the Editor: I read with great interest the manuscript entitled “Proximal Interruption of the Pulmonary Artery” (PIPA) from Williams et al,1 published in the Journal of Thoracic Imaging. The authors should be commended for the excellent review of this rare, but intriguing, condition. One important differential diagnosis might have been forgotten, however, and it is certainly worth mentioning: unilateral pulmonary vein atresia.2 Several radiographic features are similar between proximal interruption of the pulmonary artery and unilateral pulmonary vein atresia, including inconspicuous hilum, ipsilateral parenchymal hypoplasia, variable degree parenchymal anormalities, mediastinal shift, and an overall lucent appearance of the affected lung. In addition, these 2 conditions may share several clinical findings, such as variable degree of dyspnea, reduced exercise tolerance, hemoptysis, and recurrent pulmonary infections. Therefore, I believe the readers would benefit from adding unilateral pulmonary vein atresia to the differential diagnosis nicely summarized in table 1 of the article.