Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Opacity in the left upper lobe representing bony island in a rib or lung nodule . The lung volumes are normal . Normal size of the cardiac silhouette . Normal hilar and mediastinal structures . . No pneumonia , no pulmonary edema . No pleural effusions .
    OUTPUT:
    
Possible lung nodule in left upper lobe . Oblique views are recommended .