Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a possible mild increase in heart size compared to ___ , taking into account the exaggaration of size caused by AP technique . In addition , there is subtle widening of the upper mediastinal silhouette , consistent with the patient 's known anterior mediastinal mass , better seen on the CT from ___ . The lungs are otherwise clear . There is no pneumothorax or pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
1 . Possible mild cardiomegaly , new from ___ . 2 . Enlargement of the upper mediastinal diameter due to anterior mediastinal mass . MRI of the chest may be useful in differentiating thymic hyperplasia from lymphoma . 3 . No acute cardiopulmonary process .