Study of preoperative diagnostic modalities in Chinese patients with superficial esophageal squamous cell carcinoma

Figure 1 A typical case of carcinoma in situ. A: ME-BLI image shows micro-vessels with a loop-like formation (type B1); B: Ultrasonography image shows hypoechoic thickening confined to the first two layers; C: Hematoxylin-eosin staining (× 40) of an endoscopic resection specimen shows that the squamous cell carcinoma is limited to the epithelium, without invasion.

Figure 2 A typical muscularis mucosal lesion. A: ME-BLI image shows type B2 vessels without loop-like formations but with a stretched and markedly elongated transformation; B: Ultrasonography image shows a hypoechoic lesion invading the third layer with continuous submucosa; C: Hematoxylin-eosin staining (× 40) of a surgical specimen shows a moderately differentiated squamous cell carcinoma invading the muscularis mucosa.

Figure 3 A typical submucosal lesion. A: ME-NBI image shows micro-vessels dilated more than three times that of B2 vessels (type B3); B: Ultrasonography image shows a hypoechoic lesion invading the fourth layer; C: Hematoxylin-eosin staining (× 20) of a surgical specimen shows a moderately differentiated squamous cell carcinoma infiltrated to the middle third of the submucosa without muscularis propria involvement.