Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate well - expanded lungs . There is a large mass in the right upper lung with vague borders , which was not previously seen in ___ . This mass measures at least 4 cm , and is concerning for malignancy . The left lung is clear . The cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Large mass in the right upper lung with indistinct borders is highly concerning for malignancy .