Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph were provided . Lungs are clear bilaterally . Cardiomediastinal and hilar contours are within normal limits . There is no evidence of pulmonary edema or pleural effusion . There is a small left apical pneumothorax . No air under the right hemidiaphragm is identified .
    OUTPUT:
    
Small left apical pneumothorax . No shift of mediastinal structures .