目的大肠侧向发育型肿瘤(LST)与大肠癌关系密切,其诊治不同于一般的隆起样肿瘤,文章总结LST内镜诊断与治疗的经验,以引起临床上对这个特殊类型肿瘤的重视。方法内镜检查发现肠道黏膜发红或粗糙、血管网不清或消失等病变,行靛胭脂染色后放大内镜观察其腺管开口类型。结果18个月中共发现34例LST 35个病变。其中黏膜内癌4例,锯齿状肿瘤2例。35个病变内镜分型颗粒均一型15个,结节混合型18个,假凹陷型2个。病变最大为68 mm×85 mm;11～20mm 8个,21～30 mm 13个,30 mm以上14个。大肠黏膜腺管开口类型ⅢL型10个,其中8个为管状绒毛状腺瘤;Ⅳ型22个,其中16个为绒毛状腺瘤,1个黏膜内癌;ⅤA型3个,均为黏膜内癌。35个病变全部即时或择期进行内镜下切除治疗,发生出血和局限性腹膜炎各1例。结论应用黏膜染色技术和放大内镜有助于LST的诊断。LST的腺管开口大多数表现为Ⅳ型或ⅢL型,ⅢL型腺管开口多为管状腺瘤,Ⅳ型腺管开口多为绒毛状腺瘤,一旦出现Ⅴ型腺管开口则表明已经有癌变发生。 Objective The laterally developing colorectal carcinoma (LST) is closely related to colorectal cancer. Its diagnosis and treatment are different from those of general protuberant tumor. The article summarizes the experience of LST endoscopy diagnosis and treatment to arouse the clinical importance of this special type of tumor. Methods Endoscopy revealed that the intestinal mucosa was red or rough, the vascular network was unclear or disappear, and the type of duct opening was magnified by endoscopy in endoscopy. Results A total of 34 LST 35 lesions were found in 18 months. Including mucosal carcinoma in 4 cases, serrated tumor in 2 cases. Thirty-five lesions were homogenized with endoscopic type particles of 15, nodular mixed type of 18, and pseudotubated type of 2. The largest lesions were 68 mm × 85 mm, 8 were 11-20 mm, 13 were 21-30 mm, and 14 were 30-30 mm. Colorectal mucosal open type ⅢL 10, of which 8 were tubular villous adenoma; type Ⅳ 22, of which 16 were villous adenoma, 1 mucosal carcinoma; Ⅴ A type 3, were mucosal cancer. Thirty-five lesions were treated with either endoscopic or endoscopic resection, one case of bleeding and localized peritonitis, respectively. Conclusion The application of mucosal staining and magnifying endoscopy is helpful for the diagnosis of LST. Most of the LST duct openings showed type IV or IIIL. Most of the type III L duct openings were tubular adenomas. The type IV duct openings were mostly villous adenomas. Once the type V duct openings appeared, it indicated that there was already a cancerous occur.