Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A large left pleural effusion is noted with associated rightward shift of mediastinal structures . A small component of this effusion appears to be loculated at the apex . Ill - defined opacity within the left apex is present . Right lung is grossly clear . Heart size is difficult to evaluate given the presence of the large left pleural effusion . No pulmonary vasculature congestion is noted . No pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Large left pleural effusion . Patchy opacity within the left apex , for which comparison with previous exams is recommended as this finding is nonspecific , and could relate to an area of infection or inflammation though neoplasm is also not excluded . If no prior exams exist , then CT with contrast is suggested for further assessment .