Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest were provided . There is a large retrocardiac density noted containing compatible with a large hiatal hernia which has been previously imaged in part on a CT abdomen and pelvis from ___ . The lungs are clear . No signs of pneumonia , pleural effusion , or pneumothorax . Mediastinal contour is normal . The heart size appears grossly within normal limits though partially obscured due to large hiatal hernia . Bony structures are intact .
    OUTPUT:
    
Large hiatal hernia , chronic . No acute intrathoracic process .