Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an well - circumscribed irregular opacity in the right upper lobe that was not seen on ___ . This can represent a pulmonary nodule in the right upper lobe vs right upper lobe pneumonia vs focal mediastinal calcification from radiation therapy . The lung volumes are normal . Normal size of the cardiac silhouette . Normal hilar and mediastinal structures . No pneumothorax . No pulmonary edema . No pleural effusions .
    OUTPUT:
    
Well circumscribed irregular opacity in the right upper lobe , not seen on ___ . This can represent a lung nodule vs right upper lobe pneumonia vs focal mediastinal calcifications in the setting of radiation therapy given patient 's history of lymphoma . Correlation with prior chest imaging is recommended . If prior imaging can not be obtained , chest CT is recommended .