Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the most recent prior chest radiograph , the moderate right pleural effusion and right middle lobe mass appear stable . The left lung is clear . The aortic knob is calcified . The heart size is normal . A left pectoral pacer , mediastinal clips and right rib deformities are stable . A sclerotic met in the T9 vertebral body is again noted .
    OUTPUT:
    
Stable appearance of right middle lobe mass and pleural effusion and since ___ .