Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a rounded region of consolidation in the left upper lobe which has been has progressed since prior examination . Elsewhere , the lungs are clear . The cardiomediastinal and hilar contours are within normal limits .
    OUTPUT:
    
Left upper lobe consolidation , progressed since prior examination , most consistent with an evolving pneumonia , however an underlying mass can not be excluded .