Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Re demonstrated are massive bilateral parenchymal opacities , demonstrating overall interval worsening in the mid and lower left lung and slight interval improvement in the right lung base . There may be a small left pleural effusion . There is no evidence of a pneumothorax . Mild cardiomegaly , has been stable compared to prior exams dated back tumor ___ . The hilar and mediastinal contours , are otherwise unremarkable .
    OUTPUT:
    
Slight interval worsening of airspace opacity overlying the mid and lower left lung , concerning for pneumonia .