Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Large left apical mass invading the mediastinum is unchanged . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable . Left pectoral transvenous pacer leads terminate in the right atrium and right ventricle .
    OUTPUT:
    
Left pectoral transvenous pacer leads terminate in the right atrium and right ventricle . No evidence of pneumothorax . Stable left upper juxtamediastinal mass .