(A) massive mediastinal Infiltration, (B) discrete node involvement, (C) central tumor with enlarged N1 lymph nodes, and (D) peripheral tumor with no mediastinal or hilar node enlargement.Reproduced from Silvestri GA et al. Methods for Staging Non-small Cell Lung Cancer. Chest 2013;145(5)Suppl. With permission from the American College of Chest Physicians.