Right Aortic Arch Simulating a Mediastinal Tumor: A Case Report

Abstract

Right aortic arch is a developmental anomaly of the large vessels ; the aortic arch lies to the right of the trachea and esophagus instead of the left side. It is frequently associated with cardiac malformations, e.g., Eisenmenger complex, 20-25 per cent of Tetralogy of Fallot)#{176} The diagnosis of right aortic arch becomes important in relation to surgical treatment. This vascular anomaly has also been known to occur independently without producing noticeable symptoms. Many cases have been discovered accidentally during routine chest examination, because of its unusual mediastinal shadow. Roentgenologically, the following features have been enumerated.2’ 1. On a posteroanterior chest film, a small mass (right aortic knob) is observed below the right sternoclavicular joint occupying an image position of the left aortic knob. No aortic knob is found at the usual site, the first left costosternal joint. 2. The esophagogram in the posteroanterior view will show left displacement of the esophagus at the height of the right aortic knob, while it is pushed forward in the right oblique view. * Presented at the sixth meeting of the Japanese Circulation Society, the TohokuHokkaido Chapter, Sendai, Japan, June 7, 1958. **From the Katsura Surgical Clinic, Tohoku University, Faculty of Medicine, Sendai Japan.