乳腺癌前哨淋巴结术中分子诊断的价值

目的 评价乳腺癌前哨淋巴结(SLN)术中分子诊断的价值.方法 选择90例患者行前哨淋巴结活检术.术中获得的SLN均垂直于长轴切割为1.5～3 mm组织块,所有组织块均术中行印片细胞学检测,奇数组织块术中行GeneSearchTM乳腺淋巴结检测,偶数组织块术中行快速冰冻病理检测并且术后行逐层切片病理检测.将BLN检测结果同病理检测做比较.结果 经过10例的学习曲线,BLN检测可以在35 min内完成,乳腺球蛋白、角蛋白-19的循环阈值与转移灶大小呈明显的负相关性(Spearman相关系数分别为0.67和0.71).BLN检测的准确性、敏感性、特异性、阳性预测值和阴性预测值分别为95.6%、93.3%、96.7%、93.3%和96.7%,其敏感性优于快速冰冻病理(P=0.07),显著优于印片细胞学(P=0.04).相对于微转移灶的检测,BLN检测的敏感性显著优于快速冰冻病理及印片细胞学(P=0.03).结论 BLN检测快速,易于操作,具有较高的准确性,其敏感性优于快速病理和印片细胞学,适合在中国进行推广.

Abstract：

Objective To evaluate the value of GeneSearchTM BLN assay as an intraoperative diagnostic method of sentinel lymph node metastases in breast cancer patients.MethodsNinety consecutive patients were involved in this study.SLNs were intranperatively identified and dissected,and then sectioned vertically to the long axis into multiple blocks.The odd blocks were tested by BLN assay and even ones prepared for frozen sectioning(FS),while all blocks were evaluated by touch imprint cytology (TIC).Post-operatively,residual tissues of the even blocks were assessed by histopathologic examination (4-6 μm thick serial sectioning permanent H&E slides were performed every 150 μm and one block made 6 slides). Results BLN assay could be performed within less than 35 min after learning curve of 10 cases.A correlation was found between cycle time values of mammaglobin or cytokeratin-19 and size of metastases,with Spearman correlation coefficients of 0.67 and 0.71,respectively.The accuracy,sensitivity,specificity,positive predict value(PPV) and negative predict value(NPV) of the assay were 95.6%,93.3%,96.7%,93.3% and 96.7%,While FS had the sensitivity,specificity,PPV,NPV of 76.7%,100%,100%,89.6%,and TIC of 73.3%,100%,100%,88.2%,respectively.The sensitivity of the assay was higher than that of FS(P=0.07),and was significantly higher than that of FS(P=0.04).When assessing patients with micro-metastases,the assay had a sensitivity of 85.7%,which was significantly higher than that of FS and TIC(P = 0.03).Conclusion G eneSearchTM BLN Assay can replace FS and TICfor the intraoperative assessment of SLN.     

前哨淋巴结活检术检测乳腺癌腋窝淋巴结转移的效果评价

区域淋巴结是否转移是影响乳腺癌患者预后的独立因素。临床已证实,对于腋窝淋巴结阴性乳腺癌患者,行常规腋窝淋巴结清除术(axillary lymph node dissection,ALND)无任何治疗意义,而且可引起许多并发症。乳腺癌前哨淋巴结     

乳腺癌前哨淋巴结活检的临床探讨

目的:评估乳腺癌前哨淋巴结活检(Senital lymph node biopsy SLNB)对预测腋窝淋巴结转移状态的价值及其临床意义.方法:临床Ⅰ、Ⅱ期原发女性乳腺癌41例,体检无腋淋巴结肿大或虽有肿大而估计非转移性.术中在原发肿瘤周围注射亚甲蓝示踪定位,行SLNB和腋淋巴结清扫(Axillary lymph node dissection ALND).术后对全部前哨淋巴结(SLN)和腋淋巴结(ALN)行常规病理检查.结果:41例中检出SLN者32例,检出率为78.0%.其中N0组25例准确度为96.0%:阳性预测符合率100%;假阴性0例,阴性预测符合率100%.N1组7例准确度仅57.1%,假阴性2例,阴性预测符合率0.结论:应用亚甲蓝示踪定位SLNB,能准确预测(T1、T2)N0M0乳腺癌患者的转移状态,宜于推广应用.     

术中快速预测乳腺癌非前哨淋巴结转移模型的建立与验证研究

背景与目的:大部分前哨淋巴结(sentinel lymph node,SLN)阳性而接受腋窝淋巴结清扫术(axillary lymph node dissection,ALND)的患者,腋窝非前哨淋巴结(non-sentinel lymph node,nSLN)并没有发生转移,因此准确预测nSLN转移至关重要.该研究将建立基于分子诊断一步核酸扩增法(one-step nucleic acid amplification,OSNA)的术中快速预测乳腺癌nSLN转移的模型,以期有效指导乳腺癌后续治疗.方法:利用2010年OSNA临床试验入组的552例患者中SLN阳性、并接受ALND的103例患者数据,建立基于分子诊断的乳腺癌NSLN转移的预测模型,并利用2015年OSNA临床试验入组的327例患者中61例符合相同条件的患者数据进行验证.结果:原发肿瘤大小、SLN总肿瘤负荷、SLN阳性数及阴性数是NSLN转移的四个独立相关因素,利用这四个因素建立预测列线图,得出建模组患者的受试者工作特征(receiver operating characteristic curve,ROC)曲线的曲线下面积(area under the ROC curve,AUC)为0.814,验证组患者的AUC为0.842.利用验证组61例患者影像学评估的肿瘤大小替代病理大小对本模型进行了验证,得出AUC为0.838,与模型验证性AUC相比差异无统计学意义(P=0.7406).结论:基于分子诊断的乳腺癌预测nSLN转移的模型既可以术中快速预测腋窝淋巴结转移风险,也可以术后常规预测,明显优于其他预测模型,对后续腋窝的处理及放疗靶区勾画具有更好的指导价值.     

乳腺癌前哨淋巴结活检的研究体会

乳腺癌手术在历史上是肿瘤外科最具代表性的治疗 ,其手术方式 ,由经典根治手术到改良根治手术以及各种保留乳房的术式 ,体现了肿瘤外科思想观念的转变与方法的探索。最终目的为 :最大限度地追求良好的治疗效果 ,最大限度地降低复发率和并发症。近年来 ,关于前哨淋巴结活检技术的研究 ,正是这一探索的继续和延伸。作者曾在本刊 2 0 0 0年第 5期上发表了他们对 30例早期乳腺癌进行前哨淋巴结活检研究的报告 ,阳性检出率 96 .7% ;与腋窝淋巴结解剖的符合比较 ,准确性 93.3% ,灵敏度 88.9%。目前 ,此研究在国内尚属起步阶段 ,必将陆续出现更多的探索成果。这项研究的关键在 :前哨淋巴结是否能完全地、准确地反映腋窝淋巴结的状态 ,同时 ,如何才能安全地以其指导腋窝淋巴结解剖的选择。对此 ,尚需积累大量的临床资料 ,进行深入探索 ,以资佐证。     

乳腺癌前哨淋巴结活组织检查术的研究进展

乳腺癌是全世界女性最常见的恶性肿瘤之一,严重威胁女性的健康和生命。乳腺癌的外科治疗不断向＂最小最有效＂的模式发展,前哨淋巴结（SLN）活组织检查术（SLNB）在此背景下应运而生。SLNB可免除腋窝淋巴结清扫术（ALND）,大大减少了ALND的并发症。近年来,一些临床研究结果提示部分SLN阳性乳腺癌患者即使不接受ALND,其预后也未受到影响,SLN阳性乳腺癌患者是否一定要行ALND的问题有待研究。     

术中细胞学检查对乳腺癌前哨淋巴结诊断应用价值的研究

目的：探讨术中细胞学检查对乳腺癌前哨淋巴结（SLN）诊断的价值。方法：对149例乳腺癌手术患者同时进行SLN术中细胞学与快速病理检查,与常规病理进行对比分析。结果：SLN术中细胞学检查诊断的敏感性、特异性和总准确率分别为86．2％、99．3％和96．7％;术中快速病理学检查的敏感性、特异性和总准确率分别为98．5％、100．0％和99．07％。两者差异无统计学意义,P〉0．05。结论：术中细胞学检查可以作为快速病理的补充或替代手段用于乳腺癌SLN的诊断,正确取材和制片是提高诊断准确率的关键。     

乳腺癌前哨淋巴结活检的临床研究

目的　探讨乳腺癌前哨淋巴结活检 (SLNB)的临床应用价值 ,分析影响检出率的相关因素。方法　在乳腺肿瘤表面或活检部位周围皮下组织注射99mTc标记的硫胶体 ,采用核素淋巴显像和γ计数器探测仪检测识别前哨淋巴结 (SLN ) ,先行SLNB ,随后行乳腺癌改良根治术。结果　 5 0例患者中SLN检出率为 96.0 % ;敏感度为 88.2 % ;准确性为 95 .8% ;假阴性为11.8% ;假阳性为 0。患者年龄 <5 0岁、原发肿瘤位于乳腺外上象限、术前穿刺活检确诊与SLN检出有关 (P <0 .0 5 ) ;是否绝经、肿瘤大小、病理类型、雌激素受体 (ER)、孕激素受体 (PR)与SLN检出无关 (P >0 .0 5 )。结论　SLNB具有安全可靠、敏感度和准确性较高等特点 ,可以正确反映大多数乳腺癌患者腋窝淋巴结 (ALN )有无转移     

国产亚甲蓝标记乳腺癌前哨淋巴结活检64例分析

[目的]评估乳腺癌前哨淋巴结活检（SLNB）对预测腋窝淋巴结转移状态的价值。[方法]64例临床Ⅰ、Ⅱ期原发女性乳腺癌，体检无腋淋巴结肿大或虽有肿大而估计非转移性，术中在原发肿瘤周围注射亚甲蓝示踪定位，进行SLNB和腋淋巴结清扫（ALND）。术后对全部前哨淋巴结（SLN）和腋淋巴结（ALN）行常规病理检查。[结果]64例中检出SLN者53例，检出率为82．8％。其中Nn组腋窝淋巴结预测准确度为91.4％，阳性预测符合率100％（5／5）；无假阴性，阴性预测符合率100％（30／30）。N1组准确度仅72．2％（13／18）。腋窝淋巴结肿大不影响SLNB成功率，但降低SLN预测ALN准确度；肿块切检后行SLNB可降低成功率；注射亚甲蓝后60min内解剖SLN不影响SLNB成功率。[结论]在肿块切检前注射亚甲蓝示踪定位，SLNB成功率高，能准确预测（T1，T2）N0M0乳腺癌患者的转移状态。     

染料法乳腺癌前哨淋巴结活检的多因素分析

目的:染料法是乳腺癌前哨淋巴结活检的方法之一,其成功率受多种因素影响.本研究旨在探讨影响染料法乳腺癌前哨淋巴结活检成功率的相关因素.方法:2007年1月-2008年8月乳腺癌患者141例,于乳晕周围注射1%亚甲蓝,实施前哨淋巴结活检,随后行腋窝淋巴结清扫,常规HE染色进行病理诊断.采用非条件logistic回归进行单因素和多因素分析.结果:126例患者检出前哨淋巴结,15例检测失败.前哨淋巴结活检成功率89.4%,假阴性率为6.82%.单因素分析结果显示,活检成功率与患者年龄、体质量指数(body mass index,BMI)、肿瘤大小、术前腋窝淋巴结状态、肿瘤分级及腋窝淋巴结阳性数≥4枚显著相关.多因素分析结果显示,年龄(OR=4.587,P=0.024)、BMI(OR=4.882,P=0.011)及腋窝淋巴结阳性数≥4枚(OR=3.143,P=0.013)是前哨淋巴结活检成功率的独立影响因素.结论:亚甲蓝示踪法是乳腺癌前哨淋巴结活检的可靠方法,其成功率与患者年龄、BMI和腋窝淋巴结转移数相关.     

Evaluation of intraoperative frozen section diagnosis of sentinel lymph nodes in breast cancer

BACKGROUND: Intraoperative frozen sections (FS) of sentinel lymph nodes (SLNs) can be used to detect metastatic disease, allowing immediate axillary lymph node dissection (ALND). However, pathological inconsistency in the SLNs diagnosis is sometimes encountered when the results of FS and permanent sections are compared. The purpose of this study was to reveal the usefulness and limitations of FS for the diagnosis of SLNs in patients with breast cancer. METHODS: We reviewed the results for 569 patients with breast cancer at stage 0-II who underwent a sentinel node biopsy between February 1998 and December 2002. SLNs were analyzed using standard FS procedures and a single section stained with hematoxylin and eosin was examined. Patients determined to have positive SLNs based on the results of the FS diagnosis immediately underwent ALND. Permanent sections were later prepared from the remaining frozen tissues and examined using hematoxylin and eosin staining without additional immunohistochemical staining. RESULTS: Seven cases (1%) with atypical cells were found in the FS diagnosis intraoperatively, which were counted as "negative" by the following analysis. The final pathology results showed metastasis in the SLN sections in 159 patients (28%), of whom 26 were diagnosed as negative by the FS diagnosis. Accuracy, specificity and the false-negative rate were 95, 100 and 16%, respectively. The mean size of the nodal metastases in the false-negative cases was significantly smaller than that in the true-positive cases (n = 72) (P < 0.01). False-negative rates for T1b, T1c and T2 were 33, 19 and 14%, respectively. The rate of micrometastasis in T1 (43%) was significantly higher than that of T2 (13%) (P < 0.01). CONCLUSIONS: FS diagnosis for SLNs is reliable. Patients with negative SLNs by the FS diagnosis can avoid reoperation for ALND. However, FS may fail to detect micrometastases, especially in cases with small tumors.     

乳腺癌术中前哨淋巴结印片细胞学的评估

乳腺癌的手术治疗发生了巨大的变化,前哨淋巴结活检是其中之一。前哨淋巴结活检可准确评估区域淋巴结状态,从而避免在腋淋巴结阴性乳腺癌中行腋淋巴结清扫术,减少手术的并发症。乳腺癌前哨淋巴结术中病理学诊断是目前限制前哨淋巴结发展成为乳腺癌的手术规范的主要原因之一,如果能够进行准确地术中诊断,就可以避免再次手术。本文对乳腺癌前哨淋巴结的术中诊断的两种主要方法印片细胞学与冷冻切片的优缺点进行比较,回顾相关机构进行术中诊断的研究结果,并且对印片对诊断前哨淋巴结中存在的问题以及可能改进的方向进行初步的探讨。     

Extra-axillary sentinel lymph nodes in breast cancer

Background  Extra-axillary locations are known sites of lymph node metastases in patients with carcinoma of the breast. Methods  A technique utilizing a gamma probe was used to identify hot spots representing sentinel nodes residing in either axillary or extra-axillary locations in 680 patients with operable, clinically node-negative breast cancer. All identified sentinel nodes were excised. Results  Results showed that extra-axillary hot spots were found in 6.5% of patients. This rate increased to 14.8% if patients were injected with 8.0 ml unfiltered Technetium-99m-Sulfur colloid. Extra-axillary metastatic disease was identified in 6.8% of patients with extra-axillary hot spots. In patients with extra-axillary drainage, pathologically-positive nodes were exclusive to extra-axillary sites (ie, no axillary metastases) in 4.5% of cases. Factors found to increase the likelihood of identifying extra-axillary hot spots included; an increased volume of injection, medial or central tumor locations and T3 primary tumors. Conclusion  Gamma probe-guided techniques can identify extra-axillary sentinel nodes, which are at risk for harboring metastatic disease. Removal of these nodes can be done with little morbidity and may improve staging in the individual patient.     

The value of intraoperative frozen section examination of sentinel lymph nodes in breast cancer

Background

Sentinel node biopsy is a standard diagnostic component for the treatment of patients with a primary mammary carcinoma. By concomitantly performing intraoperative lymph node biopsy and primary tumor resection, patients with a positive sentinel node (SN) are not subjected to the inconvenience and risks of second surgical intervention. The aim of this retrospective study was to determine the sensitivity, accuracy and long-term consequences of the frozen section (FS) examination of the SN in breast cancer patients.

Methods

Sentinel lymph node biopsy was performed in 615 patients with an invasive tumor of the breast. Frozen sections of the SN were taken from the optimal cross-sectional surface. Serial sections were made from the remaining SN and stained using hematoxylin–eosin and immunohistochemistry.

Results

Sentinel node frozen biopsy accurately predicted the state of the axilla in 559 (90.7%) patients. There were 50 false-negative findings in patients with sentinel node metastases. The sensitivity and specificity of the intraoperative frozen section examination were 71.6% and 100%, respectively. Follow-up (mean 36.3 months) of all false-negative cases showed no development of local axillary recurrence. The results demonstrated no significant relation between tumor size and frozen section sensitivity. Frozen section investigation was less sensitive in ascertaining micrometastases (sensitivity 61.1%) than macrometastases (sensitivity 84.0%, p < 0.001).

Conclusion

Intraoperative frozen section examination of the sentinel node is a useful predictor of axillary lymph node status in breast cancer patients. Seventy-two percent of the patients with metastatic disease were correctly diagnosed and spared a second surgical procedure.     

Accuracy of intraoperative imprint cytology of sentinel lymph nodes in cT1 infiltrating breast cancer

BackgroundIntraoperative examination of sentinel lymph nodes (SLN) in breast cancer can avoid a new surgical procedure in case of positive SLN, but its value, efficacy and the methods used are still controversial. The aim of our study was to evaluate the imprint cytology intraoperative method of SLN analysis performed at our institution.MethodsWe did a retrospective study of the sentinel lymph node procedures performed during a period of 24 months on cT1N0 unifocal breast cancers. Intraoperative procedure was mainly by imprint cytology (touch prep).ResultsA SLN procedure was performed on 187 women with 360 SLN. Two hundred and seventy-seven SLN among 156 women were analyzed intraoperatively by touch prep. 19/48 positive SLN were detected by intraoperative touch prep (sensitivity 39.6%; specificity 100%; positive predictive value 100%; negative predictive value 88.7%, accuracy 89.5%). False negative rate of cytological intraoperative examination of SLN was 11,2% by SLN and 18,3% by patient. By univariate analysis, this rate significantly increased with lymphovascular invasion, tumor size cT1b and c and histological SBR grade 2 or 3. By multivariate analysis, only lymphovascular invasion was a predictive factor of intraoperative touch prep failure (OR = 3.3; IC 1.3-8.4).ConclusionIntraoperative imprint cytology of SLN in breast cancer is associated with a high rate of false negativity that questions its use in this setting.     

The feasibility of intraoperative diagnosis of sentinel lymph node metastases in breast cancer

BACKGROUND AND OBJECTIVES: The aim of the study was to analyse in detail the feasibility of intraoperative assessment of sentinel lymph nodes in breast cancer. METHODS: Altogether 139 consecutive breast cancer patients with metastases in axillary sentinel nodes were included in a prospective study. A combination of imprint cytology and frozen section was used as the method of intraoperative diagnosis of sentinel node metastases. The definite postoperative evaluation of the sentinel nodes was taken as the gold standard. RESULTS: The overall sensitivity of intraoperative diagnosis was 83%, reaching 81% if the intraoperative assessment had been limited to the two first retrieved sentinel nodes. False negative (FN) findings were more common in connection with invasive lobular carcinoma (28%) than with invasive ductal carcinoma (8%) (P < 0.01) as well as in connection with micro-metastases, in 38% of the cases, compared to the larger metastases, 6% (P < 0.00005). CONCLUSIONS: Intraoperative examination of sentinel lymph nodes enables breast surgery, axillary staging, and treatment in the same operation in a substantial proportion of breast cancer patients. Hospital costs as well as workload in the pathology laboratory may be reduced, limiting the intraoperative assessment to the two first retrieved nodes.     

乳腺癌前哨淋巴结规范化处理

前哨淋巴结活检术（sentinel lymph node biopsy, SLNB）标志着乳腺癌淋巴结手术进入微创时代,循证医学I类证据支持SLNB是临床腋窝淋巴结阴性早期乳腺癌患者安全、有效的腋窝诊断技术,前哨淋巴结阴性及低肿瘤负荷患者行SLNB替代腋窝淋巴结清扫术后,腋窝淋巴结复发风险和并发症极低。作为乳腺癌区域淋巴结微创诊断技术,SLNB安全有效替代腋窝淋巴结清扫术应建立在规范化操作前提下。目前SLNB在我国早期乳腺癌患者中逐渐趋于规范化和普及化,本文将对临床实践中SLNB的适应证、示踪剂应用、学习曲线掌握、手术规范操作和组织标本处理等问题进行综述。      

乳腺癌前哨淋巴结微小转移的检测

目的探讨检测乳腺癌前哨淋巴结(SLN)微小转移的最佳方法,研究临床病理因素与微小转移的相关性。方法应用同位素法检测乳腺癌SLN;对常规病理检查阴性的SLN,以100μm为间隔,进行多层间隔连续切片,并做HE和免疫组化染色检测微小转移;取肿瘤标本进行连续切片,并行免疫组化染色。结果共检测59例患者的121枚SLN和44份肿瘤标本,有14例(23.7%)患者的17枚(14.O%)SLN有微小转移。用HE染色法,切片数量从1层增加到3层时,微小转移的检出例数分别为3、7和10例;在3个层面上行间隔连续切片,HE分别与AE1/3、CK19和muc1联合检测时,微小转移的检出例数分别为14、12和16例。增加切片数量或采用联合检测的方法,可以提高微小转移的检出数量,微小转移与原发肿瘤大小、c-erbB2、MMP-2和血管内皮生长因子(VEGF)的表达相关。结论检测SLN微小转移的最佳方法为间隔100μm、在2个层面上行间隔连续切片,同时进行HE和muc1染色,可以检出绝大多数的微小转移。     

Stereoscopic scintigraphic imaging of breast cancer sentinel lymph nodes

BACKGROUND: Lymphoscintigraphy is used preoperatively to identify sentinel lymph nodes (SLNs). Conventional planar scintigraphy cannot provide three-dimensional(3D) information for SLN biopsy. We applied stereoscopic imaging to preoperative lymphoscintigraphy to obtain 3D information and evaluated its usefulness. METHODS: Forty-four clinical stage I breast cancer patients (1 male, 43 females; age, 59.4+/-11.4 years) were enrolled in this study. Three hours after the injection of Tc-99m, 10 degrees of oblique images and routine anterior and lateral images were acquired. Anterior and lateral stereoscopic images were obtained in all studies, except for 2 patients; only lateral views were done for those. Two experienced radiologists enumerated the visualized hot nodes. RESULTS: Stereoscopic imaging delineated more hot axillary lymph nodes compared to routine planar imaging in 8 of 42 patients (19.0%) on anterior view, 5 of 44 patients (11.4%) on lateral view, and 11 of 44 patients (25.0%) on either the anterior or lateral view. Statistically significant differences were observed between stereoscopic and routine planar imaging method on the anterior (p=0.012) and the lateral views (p=0.043). The stereoscopic imaging provided 3D information and effectively separated closely located hot nodes that were viewed as one hot node on conventional planar images. Thirty-eight out of 42 cases (90%) with anterior stereoscopic images identified the same number or more axillary hot nodes compared with lateral stereoscopic images. CONCLUSION: The stereoscopic imaging method could improve the preoperative identification of SLNs. This method is technically simple, and could be a powerful diagnostic tool for SLN imaging breast cancer.     

Pathologic examination of sentinel lymph nodes in breast cancer.

Lymphatic mapping with selective sentinel lymphadenectomy allows accurate pathologic examination of the nodes most likely to contain macro- or micrometastastic disease for staging and proper adjuvant chemotherapy. The hypothesis of SLN biopsies was histopathologically validated by Turner et al that if the node is tumor free by H&E and immunohistochemistry, the probability of non-SLN involvement is less than 0.1%. Giuliano et al and Veronesi et al reported that detection of metastases in SLNs by frozen section technique is 89% and 64%, respectively. At MCC, frozen section evaluation of SLN is not performed because of its potential loss of micrometastasis in the cryostat, freezing artifacts, sampling error, and perhaps radioactive contamination. Intraoperative detection of macro- or micrometastasis is critical because it enables conversion of patients with positive SLN to CLND in one surgical setting more cost-effectively. IIC of the lymph nodes has been used routinely in the diagnosis of hematologic malignancies and also in breast cancer as a useful method in many series. In the author's experience, IIC by Diff-Quik stain converted 100% of grossly positive and suspicious SLNs and 22% of grossly negative SLNs. The significance of detecting micrometastases in axillary lymph nodes using immunohistochemical techniques has been reported in many series. At the MCC, routine use of CKI on paraffin sections of grossly negative SLNs enabled the upstaging of 10.6% of patients from N0 to N1. Recent addition of intraoperative rapid CKI as an adjunct to complement Diff-Quik stain has proven to be more sensitive in detecting micrometastases than using Diff-Quik stain alone. IIC technique using either Diff-Quik stain or CKI requires intensive training and experience to avoid potential pitfalls and errors in interpretation. Evaluation of SLN should use methods that enhance the ability to detect micrometastasis, however, in a cost-effective manner. The cost-effectiveness of IIC by Diff-Quik stain is incomparable with frozen section evaluation. The added cost of routine immunohistochemical stain and perhaps multiple levels of H&E stain should be offset by the decreased costs of IIC and clinically by treating most patients in the outpatient settings. In summary, IIC by Diff-Quik stain is simple, rapid, and has excellent diagnostic accuracy in grossly positive and suspicious SLNs allowing cost-effective, immediate CLND. IIC by CKI is an extremely useful ancillary technique that complements Diff-Quik stain in detecting micrometastases particularly in low grade ductal or lobular carcinoma and low tumor cell volume. Appropriate combined use of both stains may lead to intraoperative nodal staging and cost-effective CLND. SLN mapping technology at MCC using IIC in conjunction with serial sections, entire tissue submission, routine use of CKI, and multiple levels of the SLN have led us to uncover micrometastasis in high-risk, traditionally node-negative patients. These results have encouraged investigators to pursue even more sensitive techniques to detect micrometastases, including molecular biology techniques such as RT-PCR. Experienced cytopathologists and active cytopathology services are required to avoid potential pitfalls in performing and interpreting IIC. More long-term follow-up and prospective trials are needed to determine the prognostic significance of upstaging by ancillary techniques, which may lead to a revision of the current TNM staging system.