Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is subtle with pneumomediastinum best visualized in the right superior mediastinal region extending superiorly into the lower right cervical region . A hazy opacity at the right lung base may represent early pneumonia . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Pneumomediastinum . No pneumothorax . A hazy opacity at the right lung base may represent early pneumonia .