肠重复畸形是一种罕见的消化道畸形，而成人结肠重复畸形更为罕见。本文报道1例22岁的女性患者，体检时发现腹腔囊性占位病变，大小约15 cm×10 cm。术中发现病变起自横结肠系膜，边界清晰。组织病理学显示囊壁具有结肠黏膜层和固有肌层等肠壁结构，局部黏膜上皮低级别异形增生，伴炎症反应，囊肿内缺乏其他脏器组织分化的成分。该患者诊断为结肠重复畸形伴上皮低级别异形增生。本文并结合文献对肠重复畸形的临床病理学特点进行分析。

Enteric duplication is a rare malformation of the digestive tract, while colonic duplication is even rarer in adults. This paper reports one case, a 22-years old female, presented with a peritoneal cystic mass lesion measured 15 cm×10 cm. The lesion was found to be from the mesentery of the colon during surgery, and sharply demarcated. It was revealed by histopathology that the cystic wall was characterized by colonic muscularis propria and mucosa layer, in which epithelium showed low-grade dysplasia, accompanied by inflammatory reactions, and lack of distinct differentiation components into other organs. Colonic duplication with epithelial low-grade dysplasia was diagnosed. The author will analyze the clinicopathological features of colonic duplication combined with literature review.