Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again seen is left apical pneumothorax . It is certainly not smaller and perhaps slightly enlarged when compared to prior . Lungs are otherwise clear . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
Persistent small left apical pneumothorax , certainly not smaller perhaps marginally larger .