Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: New collapse of the left upper lobe around a large , obstructing , left hilar mass explains leftward shift of the mediastinum and elevation of the left lung base though subpulmonic pleural effusion is probably also present , and aeration of the left lower lobe is poor , probably also due to bronchial obstruction . Patient has had right upper lobectomy . There may be a small right pleural effusion . There is no evidence for pneumothorax . The visualized osseous structures are unremarkable .
    OUTPUT:
    
1 . New upper lobe collapse and some lower lobe atelectasis around a large obstructing left hilar mass . 2 . Probable small bilateral pleural effusions .