case_images: PMC9934923_01
case_images: (A) A type 0-IIa lesion under white light endoscopy, approximately 1*1 cm in size, located in the middle of the esophagus and 28-29 cm from the incisors; (B) Esophageal lesion under blue laser endoscopy; (C) The background staining was positive under blue laser imaging magnifying endoscope. The JES type was B1, and the AVA type was small AVA. (D) Five-layer structure of the esophageal wall at the lesion was clear, and the mucosal layer was slightly thickened under ultrasound endoscope. (E) Esophageal wound after ESD. (F) An 18*14 mm esophageal mucosal tissue.
case_images: fonc-13-1072336-g001.jpg
case_images: PMC9934923_01_fonc-13-1072336-g001.jpg
case_images: f1
case_images: A type 0-IIa lesion, approximately 1*1 cm in size, was located in the middle of the esophagus and 28-29 cm from the incisors ( Figure 1A ). Blue laser imaging magnifying endoscopy (BLI-ME) revealed positive background staining ( Figures 1B, C ). Endoscopic ultrasonography suggested that the five-layer structure of the esophageal wall at the lesion was clear, and the mucosal layer was slightly thickened ( Figure 1D ). ESD was performed to remove the diseased mucosa, and 18*14-mm esophageal mucosal tissue was obtained ( Figures 1E, F ).
case_images: Translucent observation of the lesion and microscopic appearance of the lesion.
case_images: fonc-13-1072336-g002.jpg
case_images: PMC9934923_01_fonc-13-1072336-g002.jpg
case_images: f2
case_images: The postoperative pathological results showed that there were two malignant tumor components in the tissue submitted for examination ( Figures 2 ,  3A ).
case_images: (A) Full view of collision carcinoma; (B) Area of collision between SqCC (up) and AdCC (down); (C) Area of SqCC; (D) Area of AdCC; (E) Immunohistochemical staining of AdCC (CD117); (F) Immunohistochemical staining of AdCC (S-100).
case_images: fonc-13-1072336-g003.jpg
case_images: PMC9934923_01_fonc-13-1072336-g003.jpg
case_images: f3
case_images: The postoperative pathological results showed that there were two malignant tumor components in the tissue submitted for examination ( Figures 2 ,  3A ). And microscopy revealed an abrupt transition between these two components that developed adjacently but never intermingled ( Figure 3B ). One of them was SqCC (approximately 4*2 cm in area) ( Figure 3C ). Another cancerous tissue was tubular and had cribriform structures with variably solid components ( Figure 3D ), which was located in the lamina propria and submucosa, with an infiltration depth of 60 mum into the submucosa (pT1b-SM1). Subsequent immunohistochemistry of this component yielded positive CD 117, S-100, p63, and CK8 staining ( Figures 3E, F ).