Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Two AP projections through the chest were obtained . A large left pleural effusion has substantially increased in size since ___ . There is minimal vascular redistribution and mild cardiomegally . The right lung is clear without effusion , consolidation or pneumothorax . An oval opacity projects over the ___ left anterior interspace .
    OUTPUT:
    
Large left effusion . The additional presence of a pneumonia or renal metastasis can not be delineated . Repeat radiographs after diuresis will be helpful . CT may eventually be required to better characterize the left lower lobe process and left upper lobe opacity .