食管癌,通常指的是原发于食管黏膜的上皮细胞及黏膜下层腺组织发生的癌,称为原发性食管癌;其中绝大多数是鳞状上皮细胞癌,约占90%以上,腺癌占5.9%,以及未分化小细胞癌占3.6%等。相对而言,人体其他组织器官起源的原发性恶性肿瘤,通过直接浸润、淋巴和血道转移,引起食管组织结构,包括肌层、黏膜下层或黏膜层的癌细胞浸润和癌变,即为继发性食管癌。鉴于食管继发性癌变的发生率较低,临床报道很少,多为个案报 Esophageal cancer, usually refers to the primary epithelial cells in the esophageal mucosa and submucosal gland tissue cancer, known as primary esophageal cancer; the vast majority of squamous cell carcinoma, accounting for more than 90% of the gland 5.9% of cancers, and 3.6% of undifferentiated small cell carcinomas. In contrast, primary malignant tumors of other tissues and organs of the human body are secondary to the infiltration and carcinogenesis of esophageal tissue, including cancer cells in the muscularis, submucosa or mucosa, by direct infiltration, lymphatic and hematogenous metastasis Esophageal cancer. In view of the lower incidence of esophageal cancer, few clinical reports, mostly case reports