The occurrence and development of esophageal cancer is a gradual process, usually from simple epithelial hyperplasia to atypical hyperplasia, where grade I atypical hyperplasia refers to heterogeneous epithelial cells occupying the lower 1/3 layer of epithelial layer, grade II atypical hyperplasia refers to heterogeneous epithelial cells occupying the lower 2/3 layer of epithelial layer, and grade III atypical hyperplasia refers to heterogeneous epithelial cells involving the whole epithelial layer. Grade III atypical hyperplasia is also called intraepithelial neoplasia or carcinoma in situ, which can further develop into invasive carcinoma. Pan Tiewen, Department of General Thoracic Surgery, Shanghai Changzheng Hospital High-grade intraepithelial neoplasia of the esophagus is a recent pathological concept that includes carcinoma in situ and severe atypical hyperplasia in the past, and in fact this concept blurs the boundary between cancer and precancerous lesions. Preoperative gastroscopy reports high-grade intraepithelial neoplasia in esophagus, and a considerable proportion of postoperative pathology is early esophageal cancer. Second, examination: ultrasound gastroscopy is the first choice of examination, which is important for diagnosis and selection of treatment modality. III. Treatment: Endoscopic treatment should be the first choice 1. Endoscopic resection (ER) Endoscopic mucosal resection (EMR) and endoscopic mucosal dissection (ESD) are good choices. Endoscopic resection does not necessarily cure or stop the progression of the lesion, and there are serious complications such as esophageal perforation and bleeding, but it gives the patient another chance outside of surgery, and the outcome is not good enough to choose surgery again. Lesion type: It is mainly applied to early cancer, precancerous lesions and flat lesions with diameter below 50px. Ultrasonic endoscopy suggests that the cancer has infiltrated within 2/3 of the submucosa and does not exceed 2/3 of the circumference of the lesion. 2.Esophagectomy For patients with extensive severe atypical hyperplasia, nodule-like disease, or patients with suspicious lymph nodes, esophagectomy should be chosen (open chest, transdiaphragmatic fissure surgery or minimally invasive thoracoscopic surgery). With the progress of surgical technology, total thoracoscopic esophagectomy and gastric substitution esophagectomy will become the first choice among surgical modes. 3.Ablation therapy Mucosal ablation can be achieved by PDT (photodynamic therapy), radiofrequency ablation (RFA), cryoablation, argon light coagulation, thermal laser ablation, etc.