大组织切片研究直肠癌在直肠系膜内及环周切缘的播散

Mesorectal Spread and Circumferential Margin Involvement of Rectal Cancer Studied on Large Slice

目的 研究直肠癌在直肠系膜内及环周切缘的播散转移规律 ,为合理施行直肠癌手术提供病理学证据。方法 对 6 2例直肠癌患者行全直肠系膜切除术 (TME) ,手术标本制作直肠及全层系膜大组织切片 ,HE染色 ,显微镜观察。结果 期病例中 ,直肠系膜外带 (左、后、右三区 )癌灶占 4 3.2 4 %。直肠侧壁肿瘤 ,系膜同侧癌灶多于对侧 (P<0 .0 5 )。远端直肠系膜内癌播散距原发灶 1～ 3.5 cm,均为 TNM 、 期患者 ,发生率为 12 .9% (8/6 2 )。肿瘤环周切缘癌浸润 (CMI)与肿瘤分化及 TNM分期相关 ,直肠不同部位 CMI发生率无明显差别 (P>0 .0 5 )。结论利用大组织切片技术 ,能够全面观察直肠、直肠系膜及其癌灶分布。系膜外带及肿瘤同侧系膜内癌灶分布较多。手术应完整切除肿瘤远端 4 cm直肠及其周围系膜。 TME减少了癌残留及环周切缘癌浸润可能 。

Objective To provide the mode of cancer distribution in the mesorectum and circumferential resection margin.Methods Large slice technique was used in the pathologic study of 62 specimens operated on following the principles of total mesorectal excision (TME). Results More than 40% of all the observed neoplastic foci were located in the outer layer of the mesorectum in Stage Ⅲ patients. Further analysis of the foci's localities with respect to the primary tumor's locality showed that ipsolateral neoplastic foci (44.44%) were significantly more than the contralateral neoplastic foci (13.33%) in the mesorectum (P<0.05). Extramural distal spread was found in 8 cases with the maximum extent of 3.5 cm. No significant difference in occurrence of circumferential margin involvement (CMI) was observed among tumors of different location, but tumors of a poorer differentiation were noted to have a higher risk of CMI.Conclusion Large slice technique offers a whole image of rectum, mesorectum, together with the position of neoplastic foci. There are outer preponderance and lateral discrepancy of neoplastic foci distribution in the mesorectum. A distal clearance margin of 4 cm would be mandatory. We advocate the adoption of TME as the baisc surgical principles in treating patients with rectal cancer and in avoiding surgery-related circumferential margin involvement.