Left-sided pleural effusion and prominence of the pulmonary segment of the cardiomediastinal silhouette, which may be consistent with a history of pulmonary hypertension or previously repaired congenital heart abnormalities. In the absence of such history, the possibility of a mediastinal mass should be considered.
Simple pleural effusion (Present) Superior mediastinal mass (Uncertain) Enlarged pulmonary artery (Uncertain)