Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: On lateral view , there is a retrocardiac opacity and hazy appearance of pulmonary vessels which may represent developing pneumonia in the correct clinical setting . There is no pleural effusion , or pneumothorax . Cardiomediastinal and hilar silhouettes are normal size .
    OUTPUT:
    
Retrocardiac opacity on the lateral view may represent developing pneumonia in the correct clinical setting .