Esophageal tumor staging with endoscopic ultrasound (EUS)

Panel A: Superficial esophageal carcinoma (T1b tumor) extending into the submucosa (third hyperechoic layer), but not into the muscularis propria (fourth layer).
Panel B: Esophageal tumor going into the muscularis propria (fourth hypoechoic layer) but not through, defining a T2 lesion by EUS criteria.
Panel C: Carcinoma of the esophagus extending through the esophageal wall and invading the adventitia (fifth layer) (T3 tumor).
Panel D: EUS image of an esophageal tumor going through the esophageal wall and extending into the pleural space, defining the tumor as a T4a lesion.