Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiographs demonstrate a large hiatal hernia and a probable small left pleural effusion . The thoracic spine demonstrates S - shaped scoliosis . The lungs are clear and there is no pneumothorax . The cardiac , hilar , and mediastinal contours are within normal limits .
    OUTPUT:
    
Large hiatal hernia and probable small left pleural effusion .