fig1

Figure 1. Examples of ENE measurement on hematoxylin-eosin-stained tissue samples of patients with HNSCC: (A) ENE < 2 mm with a small area of capsular disruption and a few malignant cells in the adjacent stroma (arrow); and (B) ENE > 2 mm (circle) as measured from the virtual external capsule border (C) to the farthest extend of the tumor (T).