Abnormal screening chest radiograph in a 21-year-old male

Clinical introduction A 21-year-old male with a medical history of scoliosis was referred for an abnormal chest radiograph performed on screening (figure 1). He was asymptomatic with good exercise tolerance. Blood pressure and heart rate were normal. The heart sounds were normal. The pulmonary examination was unremarkable. A treadmill test performed 3 years prior for atypical chest pain was normal. An ECG performed was also normal. Question What abnormality is present in the chest radiograph? Dextrocardia Enlarged right heart border Mediastinal mass Prominent pulmonary vasculature Situs inversus