内镜超声对结直肠癌术前分期的评价

Endoscopic Utirasonography in Pre-operative Staging of Colorectal Carcinoma

目的 :探讨内镜超声 (endoscopicultrasonography ,EUS)在结直肠癌术前TNM分期中的应用价值。 方法 :对 81例手术切除的结直肠癌患者术前行内镜超声检查 ,所有病例术后均得到病理证实。结果 :EUS检查发现正常结直肠壁表现为5层结构 ,第 1 ,3,5层表现为高回声 ,第 2 ,4层表现为低回声。第 1 ,2层为黏膜层 ,第 3层为黏膜下层 ,第 4层为固有肌层 ,第 5层为浆膜下和浆膜层。EUS下结直肠癌表现为低回声肿块 ,其回声强度介于第 3层高回声和第 4层低回声之间。根据EUS下结直肠壁 5层结构和邻近器官的改变判断肿瘤侵犯的深度 ,进行T分期诊断。肿瘤旁直径≥ 5mm圆形的低回声病灶诊断为转移性淋巴结。EUS对结直肠癌T分期诊断总的准确率为 82 7% ,周围淋巴结转移诊断的敏感性和特异性为5 5 4 %和 6 8 7%。结论 :EUS对结直肠癌侵犯深度的判断有较高的准确率 ,对术前TNM分期诊断有一定价值。

Objective:To assess the value of endoscopic ultrasonography (EUS) in pre operative TNM staging of colorectal carcinoma.Methods:81 patients with colorectal carcinoma proven pathologically after surgical resection were given EUS examination before operation.Results:Normal colorectal wall was visualized by EUS as a five layered sturcture. The first, third and fifth layers were hyperechoic, the second and fourth layers were hypoechoic. The first and second layers comprised the mucosa, the third layer the submucosa, the fourth layer the muscularis propria,and the fifth layer the subserosa and serosa (adventitia). Colorectal carcinoma appeared as a hypoechoic mass with an intermediate echo level between the third hyperechoic and the fourth hypoechoic layers. The depth of the tumor invasion and T staging diagnosis were based on the changes of these layer sturctures and adjacent organs. Metasatic lymph node was defined as pericolonic,hypoechoic mass lesion with a size ≥5mm in diameter. EUS had an overall accuracy rate of 82.7% in the diagnosis of T staging of colorectal cancer. The sensitivity and specificity of EUS in the diagnosis of lymph node metastasis were 55.4% and 68.7%.Conclusion:EUS has a high accuracy in determining the depth of colorectal carcinoma.and has some value in pre operative TNM staging. The pre operative EUS may provide much information and influence the choice of therapy.