Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . The heart size is normal . No configurational abnormality is identified . The aortic arch is obliterated by a very large left upper lobe pulmonary mass that obliterates practically the entire upper hemithorax above the hilar region . Hilar structures prominence is suspicious for extension into vessels . Local pleural densities are observed along the entire left lateral chest wall , and the lower left lateral pleural sinus is mildly blunted . The lateral view confirms the lesion and identifies its location mostly in the anterior apical chest . The right - sided hemithorax remains normal with no pulmonary abnormalities and free pleural spaces . Skeletal structures of the thorax are grossly unremarkable .
    OUTPUT:
    
Unchanged appearance of large lung mass in left upper half of thorax .