Combination of concurrent endoscopic submucosal dissection and modified peroral endoscopic myotomy for an achalasia patient with synchronous early esophageal neoplasms

Figure 4 Endoscopic submucosal dissection procedure and pathological examination. A-D: Marking around the lesion using Dual knife; submucosal injection of 10 mL saline with 0.3% indigo carmine and 1:100000 epinephrine; cutting open the mucosa; the submucosa was stripped and the lesion was completely resected; E, F: Pathological examination of the resected specimen revealed high-grade intraepithelial neoplasia with a component of scattered low-grade intraepithelial neoplasia. Both of the lateral and vertical margins were negative of tumor.