体外法前哨淋巴结活检在结直肠癌分期中的应用(一)

【关键词】 结直肠癌；,体外研究；,淋巴结；,免疫组化

　　Application of ex vivo sentinel lymph node biopsy in the staging of colorectal cancer

　　【Abstract】 AIM: To explore whether ex vivo sentinel lymph node (SLN) biopsy can be easily applied in improving the auracy of pathologic staging for colorectal cancer （CRC）. METHODS: The specimens from 26 patients (14 males, 12 females) with CRC were freshly (within 5 min) delivered to pathological examination and underwent ex vivo SLN biopsy. SLNs were identified as the 1st to 4th blue stained nodes after ex vivo submucosal peritumoral injection of 10 g/L isosulfan blue (IB) dye. The SLNs were sectioned and examined histologically by HE staining. Additional immunohistochemical staining for cytokeratins was performed when bluestained lymph nodes were negative by HE staining. RESULTS: Of the 26 specimens, SLNs were identified by ex vivo SLN biopsy in 23 (88.5%). In the 11 cases where the SLNs were negative in HE staining for micrometastases and in immunohistochemical staining for cytokeratins, all other nonSLNs in the specimens were also negative (0% false negative rate). The SLN was positive for micrometastases by HE staining in only 8 (30.7%) cases; the other 4 (15.3%) cases with negative nodes by HE staining were demonstrated positive for micrometastases through immunohistochemical staining for cytokeratins. CONCLUSION: Ex vivo SLN biopsy mapping is a feasible technique for the staging of CRC, especially in bination with immunohistochemical staining for cytokeratins, which offers reference for the assisted chemotherapy of CRC patients.

　　【Keywords】 colorectal neoplasms; in vivo; lymph node; micrometastases; immunohistochemistry

　　【摘要】 目的：探讨体外法结直肠癌前哨淋巴结(SLN)定位活检的可行性及其对肿瘤分期的影响. 方法：结直肠癌患者26 (男14,女12)例,年龄37～83岁,应用10 g/L异硫蓝(IB)染料于肿瘤离体5 min内用体外定位的方法对其SLN进行定位,蓝染的第1~4个淋巴结为SLN. 常规HE染色蓝染的SLN行组织病理学检查;对常规检查为阴性的SLN进行抗细胞角蛋白免疫组织化学染色，检测阳性染色的淋巴结. 结果：体外SLN定位法共检测出SLN者23例(88.5%, 23/26); 其中11例患者SLN微转移灶常规HE染色及抗细胞角蛋白免疫组织化学染色检测均为阴性，其根治性切除的标本中非SLN的区域淋巴结亦均为阴性(假阴性率为0)；常规HE染色在8例患者SLN中检测出微转移灶(30.7%)，另4例患者为HE染色阴性而抗细胞角蛋白免疫组化染色证实存在微转移灶(15.3%). 结论：体外结直肠癌SLN定位活检术准确性高，同时联合应用抗细胞角蛋白免疫组化染色可以提高肿瘤分期，为应用辅助化疗改善患者预后提供依据.

　　【关键词】 结直肠癌；体外研究；淋巴结；免疫组化

　　0　引言

　　结直肠癌(colorectal cancer, CRC)隐匿性微转移灶(micrometastasis, MM)的漏诊而未行化疗是影响结直肠癌患者预后的因素〔1-5〕. 前哨淋巴结(sentinel lymph node, SLN)定位活检技术可明显提高淋巴结检出数量〔6-8〕及MM的诊断率〔4-8〕. 我们探讨体外SLN定位活检技术的可行性及其临床意义，特别是对于肿瘤分期的影响，为辅助化疗,改善患者预后提供理论依据.

　　1　对象和方法

　　1.1对象

　　200406/200603,经西安交通大学医学院第一附属医院肿瘤外科确诊的CRC,有手术根治可能且无手术禁忌证患者26（男14，女12）例,年龄37～83平均（60. 2,中位60）岁. 其中结肠癌17例,直肠癌9例. 所有患者术前皆经内镜检查活检确诊.

　　1.2方法

　　所有患者行标准的根治术，联合区域淋巴结清扫术，标本移出5 min内，沿肠管长轴于对系膜缘切开，于肿瘤周围分4点黏膜下或浆膜下注射10 g/L异硫蓝染料共2 mL，轻柔按摩注射点约2～5 min，以促进淋巴回流〔7-9〕. 追踪辨认蓝染的第1~4个淋巴结为SLN （图1），标本用100 g/L甲醛固定. 首先常规HE染色检查上述甲醛固定的各淋巴结及SLN,确定SLN与区域淋巴结的转移情况. 对常规病理学检查为阴性的SLN进行免疫组化法染色：链霉亲和素生物素免疫过氧化物酶方法（SP法）. MM按国际抗癌联盟的推荐定义为单个转移肿瘤细胞或细胞团φ≤2 mm.