congenital pseudohorseshoe lung associated with scimitar syndrome

abstract horseshoe lung is a congenital pulmonary malformation that is usually associated with scimitar syndrome. this malformation consists of fusion of both pulmonary lobes from the posterobasal segments. the fusion appears in the retrocardiac area, in front of the esophagus and thoracic aorta. pleural separation of pulmonary lobes distinguishes pseudohorseshoe appearance from a true horseshoe lung. scimitar syndrome known as hypogenetic lung syndrome is a part of the congenital pulmonary venolobar syndrome. it is a partial anomalous pulmonary venous return with pulmonary hypoplasia. scimitar vein is an anomalous drainage vessel between the right pulmonary lobe vessels and the inferior vena cava. the appearance of the vessel resembles turkish scimitar; therefore, the syndrome is called scimitar syndrome. we hereby report a 61-year-old woman with adult form congenital scimitar syndrome and will describe the imaging findings of pseudohorseshoe lung appearance.