Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A small left - sided pleural effusion is new from ___ , unexplained . No pleural effusion on the right . No pneumothorax . There is no consolidation or pulmonary edema . Aorta is tortuous . Mild cardiomegaly is unchanged .
    OUTPUT:
    
Unexplained small left pleural effusion , new from ___ .