OBJECTIVETo discuss the significance of pathological diagnosis of colorectal intraepithelial neoplasia and its treatment principles.

METHODSOne hundred and fifty-eight cases with colorectal tumors were treated between January 2004 and June 2008, among them 73 cases of tumors were diagnosed as low grade intraepithelial neoplasia and 89 tumors as high grade intraepithelial neoplasia on biopsy. Five patients with adenoma were treated with endoscopic polypectomy, 49 patients with radical colectomy, 74 patients with low anterior resection (LAR), 16 patients with local excision, 2 patients with Hartmann operation, 4 patients with abdominal perineal resection, 7 patients with Parks coloanal anastomosis and 1 patient with sigmoid colostomy. The postoperative pathological examination result was compared with preoperative biopsy examination.

RESULTSWith postoperative pathological examination, 109 cases (67.3%) were identified as infiltrative adenocarcinoma, among them 80 cases (89.9%) had been diagnosed as high grade intraepithelial neoplasia and the other 29 cases (39.7%) had been diagnosed as low grade intraepithelial neoplasia before the operation. In patients with infiltrative adenocarcinomas, 2 cases developed hepatic metastasis, 18 were classified as phase T4, and 26 cases (23.9%) were found with lymph nodes metastasis after the operation.

CONCLUSIONSWe should pay more attention to tumors with a diagnosis of intraepithelial neoplasia due to its high potential of malignancy. When the lesion was highly suspected to be malignant, and the resection of the tumor would save the anal sphincter, the tumor should be treated with segmental resection. If the tumor could be confirmed as a infiltrating one then a curative resection is the first choice.