Strategies for optimizing pathologic staging of sentinel lymph nodes in breast cancer patients

Due to the extensive pathologic evaluation of the sentinel lymph node (SLN), micrometastases are frequently observed. If micrometastases are clinically relevant, the histopathologic examination of SLNs should be sensitive enough to detect them. The probability of detecting micrometastases was calculated when examining the SLN according to the current Dutch pathology protocol and strategies evaluated to optimize the chance of detection. The dimensions of 20 consecutive axillary SLNs in patients with cT1-2N0 breast cancer were measured. In a mathematical model, the probability of detecting micrometastases in a SLN was calculated. Similarly, strategies to optimize the probability of detecting micrometastases were explored. When applying the pathology guidelines, the calculated probability to detect a micrometastasis was 18% for a 200-microm micrometastasis and 69% for a 2.0-mm metastasis in a median sized SLN. To detect the smallest micrometastasis in a median-sized SLN with a 95% probability, the interval between the sections must be decreased to 200 microm, and 20 levels from both halves must be examined. Given a prognostic significance of micrometastases, our current pathology guidelines are not sensitive enough. The number of sections should be increased, while the interval between cuts should be no more than 200 microm.     

In breast cancer patients sentinel lymph node metastasis characteristics predict further axillary involvement

The aim of the study was to correlate various primary tumor characteristics with lymph node status, to examine sentinel lymph node (SLN) metastasis size and non-SLN axillary involvement, to look for a cut-off size/number value possibly predicting additional axillary involvement with more accuracy and to examine the relationship of SLN metastasis size to overall survival. Of 301 patients who underwent SLN biopsy, 75 had positive SLNs. The size of the metastases was measured. For different size categories, association with the prevalence of non-SLN metastases was assessed. Associations between metastasis size and tumor characteristics and overall survival (OS) were studied. The prevalence of axillary lymph node (ALN) involvement was not significantly different between cases with micrometastasis or macrometastasis in SLNs (p?=?0.124). However, for metastases larger than 6, 7, and 8 mm, the prevalence of ALN involvement was significantly higher (p?=?0.046, 0.022, and 0.025). OS was significantly lower in SLN-positive than in SLN-negative cases (p?=?0.0375). Primary tumor size larger than 20 mm was associated with a significantly higher incidence of SLN metastasis (p?<?0.001), and primary tumor size over 26 mm was associated with additional positive non-SLN (p?<?0.001). Higher mitotic index (≥7) in primary tumors was significantly (p?<?0.001) associated with ALN involvement in SLN-positive cases, whereas higher Ki67 labeling index was not significantly correlated with SLN or ALN involvement. Lymphovascular invasion (LVI) in primary tumors was significantly correlated with SLN positivity (p?<?0.001) but not with further ALN involvement or OS. Tumor size and LVI are predictive for SLN metastasis. Mitotic index, primary tumor size, and larger volume SLN involvement are determinants of further ALN involvement. SLN metastasis size over 6 mm is a strong predictor of further axillary involvement. OS is shorter in the presence of positive SLN.     

Sentinel lymph nodes for breast carcinoma: an update on current practice

Sentinel lymph node (SLN) biopsy has been established as the standard of care for axillary staging in patients with invasive breast carcinoma and clinically negative lymph nodes (cN0). Historically, all patients with a positive SLN underwent axillary lymph node dissection (ALND). The ACOSOG Z0011 trial showed that women with T1–T2 disease and cN0 who undergo breast‐conserving surgery and whole‐breast radiotherapy can safely avoid ALND. The main goal of SLN examination should be to detect all macrometastases (>2 mm). Gross sectioning of SLNs at 2‐mm intervals and microscopic examination of one haematoxylin and eosin‐stained section from each SLN block is the preferred method for pathological evaluation of SLNs. The role and timing of SLN biopsy for patients who have received neoadjuvant chemotherapy is controversial, and continues to be explored in clinical trials. SLN biopsies from patients with invasive breast carcinoma who have received neoadjuvant chemotherapy pose particular challenges for pathologists.     

乳腺癌前哨淋巴结术中分子诊断的临床实用性初探

目的 探讨GeneSearchTM乳腺淋巴结检测试剂盒(以下简称GeneSearch)在乳腺癌前哨淋巴结(SLN)术中诊断的临床实用性.方法 对复旦大学附属肿瘤医院2009年2月至6月诊治的88例乳腺癌患者行SLN活检.首先垂直长轴将所得淋巴结切成数块厚约2 mm的组织块,对各切面进行术中细胞印片后,奇数号组织块用于术后连续切片检查,偶数号组织块采用GeneSearch进行检测,应用即时荧光定量逆转录聚合酶链反应检测SLN中CK19和乳腺球蛋白表达的Ct值.将GeneSearch以术后连续切片的诊断为准,与术中细胞印片、术后连续切片的病理结果分别进行比较.结果 88例共获得225枚SLN,其中宏转移淋巴结27枚,微转移淋巴结9枚,阴性淋巴结189枚(其中5枚为孤立肿瘤细胞).从切割淋巴结开始到最终形成报告,GeneSearch耗时范围为35～45 min(平均40 min).基于淋巴结数目,GeneSearch与术后连续切片的总体符合率为95.6%(215/225),其检测敏感度为86.1%(31/36),均高于术中细胞印片[分别为94.7%(213/225)和72.2%(26/36)].SLN转移灶大小与CKl9和乳腺球蛋白的Ct值存在统计学相关性(P＜0.01).结论 GeneSearch用于SLN术中诊断时,其检测敏感度高于术中细胞印片,达到比较满意的效果,但在应用中仍存在一些问题.     

Histopathological patterns of melanoma metastases in sentinel lymph nodes

AIMS: Sentinel lymph node biopsy (SLNB) is an important component in the staging and treatment of cutaneous melanoma (CM). The medical literature provides only limited information regarding melanoma sentinel lymph node (SLN) histology. This report details the specific histological patterns of melanoma metastases in sentinel lymph nodes (SLNs) and highlights some key factors in evaluating SLNs for melanoma. METHODS: From 281 SLNB cases between June 1998 and May 2002, 79 consecutive cases of SLN biopsies positive for metastases from CM were retrospectively reviewed. The important characteristics of the SLNs and the metastatic foci are described. RESULTS: The median size of positive SLNs was 17 mm (range, 5-38). SLNs had a median of two metastatic foci (range, 1-11), with the largest foci being a median of 1.1 mm in size (range, 0.05-24). S-100 and HMB-45 staining was positive in 100% and 92% of the detected metastatic foci, respectively. The metastatic melanoma cells were epithelioid, spindled, and mixed in 86%, 5%, and 9% of cases. Metastatic foci were most often (86%) found in the subcapsular region of the SLN. Benign naevic cells were found coexisting in 14% of positive SLNs. CONCLUSIONS: Staining for S100 is more sensitive than HMB-45 (100% v 92%), but HMB-45 staining helped to distinguish benign naevic cells from melanoma. The subcapsular region was crucial in SLN evaluation, because it contained the metastases in 86% of cases. Evaluation of the subcapsular space should not be compromised by cautery artefacts or incomplete excision of the SLN.     

Sentinel lymph node investigation in melanoma: detailed analysis of the yield from step sectioning and immunohistochemistry

AIMS: To evaluate in detail the extent to which step sectioning and immunohistochemical examination of sentinel lymph nodes (SLNs) in patients with melanoma reveal additional node positive patients, to arrive at a sensitive yet workable protocol for histopathological SLN examination. METHODS: The study comprised 29 patients with one or more positive SLN after a successful SLN procedure for clinical stage I/II melanoma. SLNs were lamellated into pieces of approximately 0.5 cm in size. One initial haematoxylin and eosin (H&E) stained central cross section was made for each block. When negative, four step ribbons were cut at intervals of 250 microm. One section from each ribbon was stained with H&E, and one was used for immunohistochemistry (IHC). RESULTS: When taking the cumulative total of detected metastases at level 5 as 100%, the percentage of SLN positive patients increased from 79%, 83%, 83%, 90% to 93% in the H&E sections through levels 1-5, and with IHC these values were 83%, 86%, 90%, 97%, and 100%, respectively. One of six patients in whom metastases were detected at levels 2-5 only had metastases in the subsequent additional lymph node dissection. CONCLUSIONS: Multiple level sectioning of SLNs (five levels at 250 microm intervals) and the use of IHC detects additional metastases up to the last level in melanoma SLNs. Although more levels of sectioning might increase the yield even further, this protocol ensures a reasonable workload for the pathologist with an acceptable sensitivity when compared with the published literature.     

Implementation of step sectioning in the examination of sentinel lymph nodes to improve the detection of micrometastases in breast cancer patients

The object of this study was to examine whether a new protocol for examination of sentinel lymph nodes (SLNs) would lead to the detection of more metastases. Sections of 1 mm would identify most SLN macrometastases, and step sections at intervals of 200-250 μm would identify most micrometastases. A total of 111 breast cancer patients who underwent the SLN procedure at St. Olavs University Hospital in Trondheim, Norway in 2008 were included in the study group. Their SLNs were processed according to a new standardized protocol with sections of 2-3 mm being step sectioned at intervals of 200-250 μm. A total of 109 breast cancer patients undergoing the SLN procedure in 2007 were used as a reference group. Metastases were found in 29% of the cases, compared with 26% in the reference group. Step sectioning of SLNs revealed metastases in five cases initially found to be negative. The metastases of the study group were smaller, with a median value of 1.25 mm compared with 4.25 mm in the reference group. Step sectioning led to the detection of metastases in SLNs initially found to be negative. The median size of the metastases was considerably smaller in the study group than in the reference group.     

A model for determining the optimum histology of sentinel lymph nodes in breast cancer

AIMS: To create and use a geometrical model for sentinel lymph node (SLN) histopathology in breast cancer. METHODS: The model involves a spherical metastasis randomly situated in an SLN. Two extreme situations are taken as the starting points. In one of these, the metastasis is seen in its largest dimension, whereas in the other it is only just visible, approximating 0 mm in size. Intermediate positions are analysed, with different metastasis sizes and different distances between the levels assessed by histology. RESULTS: The findings suggest that sections taken 1 mm apart afford a reasonable means of identifying almost all metastases measuring > 2 mm (referred to as macrometastases here). For nearly all micrometastases to be identified correctly according to the current TNM definitions (that is, metastases > 0.2 mm), a step sectioning protocol with levels of 250 microm or 200 microm would be adequate. CONCLUSIONS: SLNs are the most likely sites of nodal metastasis. Macrometastases are of recognised prognostic relevance so that all should be identified, preferably correctly as macrometastases; an assessment of levels 1 mm apart appears satisfactory and sufficient for this aim. SLNs also offer an ideal method for the study of the significance of micrometastases; for this, step sections separated by 200 or 250 microm are a good choice.     

Micromorphometric features of positive sentinel lymph nodes predict involvement of nonsentinel nodes in patients with melanoma

The aim of the present study was to determine whether micromorphometric features of positive sentinel lymph nodes (SLNs) from patients with melanoma are useful for predicting further nodal involvement in completion lymph node dissection (CLND) specimens. Of 986 patients with melanoma undergoing SLN biopsy between March 1992 and February 2001, 175 (17.7%) had at least 1 positive SLN and 140 had subsequent CLND specimens available for review. Further nodal involvement in CLND specimens was present in 24 (17.1%) of 140 patients. Of 8 micromorphometric features of the SLNs that were assessed, the presence of metastases in CLND specimens was correlated significantly with a tumor penetrative depth (maximum distance of melanoma cells from the inner margin of the SLN capsule) of more than 2 mm (P < .05), a deposit size of more than 10 mm2 (P < .01), the presence of melanoma cells in perinodal lymphatic vessels (P < .01), and the effacement of nodal architecture by metastatic melanoma cells (P < .05). Our results indicate that some morphologic features of melanoma metastases in SLNs predict the likelihood of further nodal involvement in CLND specimens.     

Non-sentinel lymph node involvement in patients with breast cancer and sentinel node micrometastasis; too early to abandon axillary clearance

AIMS: It has been suggested that patients with T1-2 breast tumours and sentinel node (SLN) micrometastases, defined as foci of tumour cells smaller than 2 mm, may be spared completion axillary lymph node dissection because of the low incidence of further metastatic disease. To gain insight into the extent of non-sentinel lymph node (n-SLN) involvement, SLNs and complementary axillary clearance specimens in patients with SLN micrometastases were examined. METHODS: A set of 32 patients with SLN micrometastases was selected on the basis of pathology reports and review of SLNs. Five hundred and thirteen n-SLNs from the axillary clearance specimens were serially sectioned and analysed by means of immunohistochemistry for metastatic disease. Lymph node metastases were grouped as macrometastases (> 2 mm), and micrometastases (< 2 mm), and further subdivided as isolated tumour cells (ITCs) or clusters. RESULTS: In 11 of 32 patients, one or more n-SLN was involved. Grade 3 tumours and tumours > 2 cm (T2-3 v T1) were significantly associated with n-SLN micrometastases as clusters (grade: odds ratio (OR), 8.3; 95% confidence interval (CI), 1.4 to 50.0; size: T2-3 tumours v T1: OR, 15; 95% CI, 2.18 to 103.0). However, no subgroup of tumours with regard to size and grade was identified that did not have n-SLN metastases. CONCLUSIONS: In patients with breast cancer and SLN micrometastases, n-SLN involvement is relatively common. The incidence of metastatic clusters in n-SLN is greatly increased in patients with T2-3 tumours and grade 3 tumours. Therefore, axillary lymph node dissection is especially warranted in these patients. However, because n-SLN metastases also occur in T1 and low grade tumours, even these should be subjected to routine axillary dissection to achieve local control.     

High CD10 expression in lymph node metastases from surgically treated prostate cancer independently predicts early death

Patients with nodal positive prostate cancers are an important cohort with poorly defined risk factors. CD10 is a cell surface metallopeptidase that has been suggested to play a role in prostate cancer progression. CD10 expression was evaluated in 119 nodal positive prostate cancer patients using tissue microarrays constructed from primary tumors and lymph node metastases. All patients underwent radical prostatectomy and standardized extended lymphadenectomy. They had no neoadjuvant therapy and received deferred androgen deprivation. In the primary tumor, high CD10 expression was significantly associated with earlier death from disease when compared with low CD10 expression (5-year survival 73.7% vs. 91.8%; p = 0.043). In the metastases, a high CD10 expression was significantly associated with larger total size of metastases (median 11.4 vs. 6.5 mm; p = 0.015), earlier death of disease (5-year survival 71.5% vs. 87.3%; p = 0.017), and death of any cause (5-year survival 70.0% vs. 87.2%; p = 0.001) when compared with low CD10 expression. CD10 expression in the metastases added independent prognostic information for overall survival (p = 0.029) after adjustment for Gleason score of the primary tumor, nodal tumor burden, and resection margins. In conclusion, a high CD10 expression in prostate cancer predicts early death. This information is inherent in the primary tumors and in the lymph node metastases and might help to personalize patient management.     

Multiparameter flow cytometry as a tool for the detection of micrometastatic tumour cells in the sentinel lymph node procedure of patients with breast cancer

AIM: To investigate whether multiparameter flow cytometry (MP-FCM) can be used for the detection of micrometastasis in sentinel lymph nodes (SLNs) in breast cancer. METHODS: Formalin fixed, paraffin wax embedded sentinel lymph nodes (n = 238) from 98 patients were analysed. For each lymph node, sections for haematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) for cytokeratin (MNF116) were cut at three levels with a distance of 500 microm. The intervening material was used for MP-FCM. Cells were immunostained with MNF116, followed by an incubation with fluorescein isothiocyanate (FITC) labelled goat antimouse immunoglobulin. DNA was stained using propidium iodide. From each lymph node 100,000 cells were analysed on the flow cytometer. RESULTS: Thirty eight of the 98 patients with breast carcinoma showed evidence of metastatic disease in the SLN by one ore more of the three methods. In 37 of 38 cases where metastatic cells were seen in the routine H&E and/or IHC, more than 1% cytokeratin positive cells were detected by MP-FCM. In 24 patients, metastatic foci were more than 2 mm (macrometastasis) and in 14 these foci were smaller than 2 mm (micrometastasis). In three of these 14 cases, MP-FCM revealed positive SLNs, although this was not seen at first glance in the H&E or IHC sections. After revision of the slides, one of these three remained negative. However, MP-FCM analysis of the cytokeratin positive cells showed an aneuploid DNA peak, which was almost identical to that of the primary breast tumour. Duplicate measurements, done in 41 cases, showed a 99% reproducibility. In five of 14 patients with micrometastasis, one or two metastatic foci were found in the non-SLN. However, in 15 of 24 macrometastases multiple non-SLNs were found to have metastatic tumour. All micrometastases except for the remaining negative one mentioned above showed only diploid tumour cells, despite the fact that their primary tumours contained both diploid and aneuploid tumour cells. In primary tumours with more than 60% aneuploid cells, predominantly aneuploid macrometastasis were found, whereas diploid primary tumours only showed diploid micrometastases or macrometastases in their SLN. Aneuploid SLN macrometastases were associated with non-SLN metastases in five of seven patients, whereas diploid cases showed additional non-SLN metastases in only seven of 16 patients. CONCLUSION: In all cases, MP-FCM was sufficient to detect micrometastatic tumour cells in a large volume of lymph node tissue from SLNs. In some cases it was superior to H&E and IHC staining. Approximately 30% of SLN micrometastases are accompanied by additional non-SLN metastases. The size of the aneuploid fraction (> 60%) in the primary tumour may influence the risk of having both SLN and non-SLN metastases.     

Intraoperative examination of the sentinel lymph node for breast carcinoma staging.

Intraoperative pathologic examination of the sentinel lymph node (SLN) draining a primary breast carcinoma allows an SLN-positive patient to undergo complete axillary lymphadenectomy as part of the same surgical procedure. However, the optimal technique for rapid SLN assessment has not been determined. We reviewed our results with imprint cytology (IC) and frozen section (FS) examination of SLNs from 278 patients. Compared with H&E-stained paraffin sections, IC and FS had an overall accuracy of 93.2%. The false-reassurance rate (false-negative results/all negative results) was 8.4%. It correctly identified 98% of macrometastases but only 28% of micrometastases. There were no false-positive results. Compared with paraffin-section cytokeratin immunohistochemistry results, the IC-FS false-reassurance rate increased to 25.8%. The false-reassurance rate decreased with smaller primary tumor size (T1 vs T2/3) and ductal type, smaller diameter of the SLN (< or = 2.0 cm), and greater pathologist experience. IC combined with 2-level FS reliably identifies SLN macrometastases but commonly fails to detect SLN micrometastases. If SLN micrometastasis is used to determine the need for further lymphadenectomy, more sensitive intraoperative methods will be needed to avoid a second operation.     

Lymphangiogenesis in breast cancer is associated with non-sentinel lymph node metastases in sentinel node positive patients

Axillary lymph node dissection (ALND) is not suggested in breast cancer patients with negative sentinel lymph node (SLN) biopsies, and SLN is the only positive node in 40-70% of the remaining cases. To distinguish a subgroup in which ALND would be omitted, we investigated the role of lymphangiogenesis in primary breast cancer as a risk factor for distal lymph node involvements in patients with positive SLNs. 86 patients were included in this study. The frequency of proliferative lymphatic endothelial cells (LECP%) was evaluated in each specimen after immunohistochemical double staining for D2-40 and Ki-67. Larger primary tumor size, increased number of positive SLNs, lymphatic vessel invasion and LECP% were significantly associated with non-SLN metastases in the univariate analysis, but only LECP% retained significance in the multivariate model. A positive correlation between LECP% and lymphatic vessel invasion was also revealed. Our study confirmed the important role of lymphangiogenesis in tumor spread, and suggested that LECP% is a promising predictor for additional axillary lymph node involvements.     

Pathologic examination of the axillary sentinel lymph nodes in patients with early-stage breast carcinoma: current and resolving controversies on the basis of the European Institute of Oncology experience

Several controversial aspects of sentinel lymph node biopsy (SLNB) for patients with early-stage, node-negative breast carcinoma have been dealt with and resolved in the past decade since its introduction. Unfortunately, however, there is still no consensus on how best to examine sentinel lymph nodes (SLN) histologically. As a consequence, the protocols for SLN examination are remarkably variable in different institutions, leading to a very poor reproducibility of the data stemming from investigations on series of patients whose SLNs have been evaluated according to diverse protocols. Patient outcomes, however, can be optimised only by standardization of the whole procedure of SLNB, with particular reference to the histopathologic scrutiny. Lack of a standardized histopathologic protocol likely derives also from the uncertainties about the clinical implications of minimal lymph node involvement (isolated tumour cells and micrometastases) with regard both to the risk of additional metastases to non-sentinel lymph nodes of the same basin and to the prognostic value for patients’ survival. This review aims at highlighting some of the controversial issues of the histopathologic examination of the SLNs, including the number of sections and cutting intervals, the use of immunohistochemistry and the role of molecular biology assays.     

Intraoperative sentinel lymph node evaluation in patients with node-positive breast cancer status post neoadjuvant systemic therapy - An institutional experience

Recent studies have shown the feasibility and utility of sentinel lymph node (SLN) biopsy in patients with biopsy proven node-positive breast cancer after neoadjuvant chemotherapy. We reviewed our experience in intraoperative SLN evaluation in such cases and its effect on axillary management. A retrospective analysis of breast cancer patients (2015–2018) with a biopsy-proven positive axillary lymph node, who received neoadjuvant systemic therapy and underwent intraoperative SLN assessment was performed. Intraoperative SLN assessment results were compared with final pathology. Its accuracy and effect on axillary management is summarized. We identified 106 patients with positive axillary lymph node and neoadjuvant systemic therapy between the ages of 28 and 75 years who had SLN biopsy and lumpectomy (33) or mastectomy (73). Three or more SLNs were identified in 91 cases (86 %). The previously biopsied lymph node was identified as one of the sentinel lymph nodes in 93 cases (88 %). There is a high concordance rate between frozen section diagnosis and final diagnosis on sentinel lymph nodes. No false positive case and seven false negative frozen section diagnosis cases (diagnosed as negative on frozen section and positive on permanent sections) were identified. False-negative frozen section diagnosis correlated with low-volume nodal disease and obscuring tumor bed changes. Almost half of the positive lymph nodes were converted to negative after neoadjuvant chemotherapy. SLN biopsy with intraoperative frozen section evaluation after neoadjuvant systemic therapy in node-positive patients is an effective way to minimize axillary surgery.     

Pathologic evaluation of sentinel lymph nodes in colorectal carcinoma

BACKGROUND: The identification of lymph node metastases in colorectal resection specimens is necessary for accurate tumor staging. However, routine lymph node dissection by the pathologist yields only a subset of nodes removed surgically and may not include those nodes most directly in the path of lymphatic drainage from the tumor. Intraoperative mapping of such sentinel lymph nodes (SLNs) has been reported in cases of melanoma and breast cancer. We applied a similar method to cases of colorectal carcinoma, with emphasis on the pathology of the SLNs. METHODS: Eighty-three consecutive patients with colorectal carcinoma were evaluated after intraoperative injection of 1 to 2 mL of 1% isosulfan blue dye (Lymphazurin) into the peritumoral subserosa. Blue-stained lymph nodes were suture-tagged by the surgeon within minutes of the injection for identification by the pathologist, and a standard resection was performed. Designated SLNs were sectioned at 10 levels through the block; a cytokeratin immunostain (AE1) was also obtained. To evaluate the possibility that increased detection of metastases in the SLN might be solely due to increased histologic sampling, all initially negative non-SLNs in the first 25 cases were sectioned also at 10 levels. RESULTS: Sentinel lymph nodes were identified intraoperatively in 82 (99%) of 83 patients and accounted for 152 (11.9%) of 1275 lymph nodes recovered, with an average of 1.9 SLNs per patient. A total of 99 positive lymph nodes (38 positive SLNs and 61 positive non-SLNs) were identified in 34 node-positive patients. The SLNs were the only site of metastasis in 17 patients (50%), while 14 patients (41%) had both positive SLNs and non-SLNs. Three patients (9%) had positive non-SLNs with negative SLNs, representing skip metastases. In patients with positive SLNs, 91 (19%) of 474 total lymph nodes and 53 (12%) of 436 non-SLNs were positive for metastasis. In patients with negative SLNs, 8 (1%) of 801 total lymph nodes and 8 (1.2%) of 687 non-SLNs were positive for metastasis. Multilevel sections of 330 initially negative non-SLNs in the first 25 patients yielded only 2 additional positive nodes (0. 6%). All patients with positive SLNs were correctly staged by a combination of 4 representative levels through the SLN(s) together with a single cytokeratin immunostain. CONCLUSIONS: Intraoperative mapping of SLNs in colorectal carcinoma identifies lymph nodes likely to contain metastases. Focused pathologic evaluation of the 1 to 4 SLNs so identified can improve the accuracy of pathologic staging.     

Intraoperative cytologic evaluation of sentinel lymph nodes in patients with breast carcinoma by scrape preparation

Intraoperative evaluation of sentinel lymph nodes (SLNs) in patients with breast carcinoma allows surgeons to complete axillary lymph node dissection in one procedure if any SLN shows metastasis. The accuracy of intraoperative pathological diagnosis is critical for decision-making. The purpose of this study was to evaluate our rapid intraoperative cytologic diagnosis of SLN through comparing with the final surgical pathologic diagnosis of the corresponding lymph nodes. A total of 454 SLNs from 159 consecutive female patients with a preoperative diagnosis of breast carcinoma over 3-year period were included in this study. After gross examination of each bisected lymph node, a scrape preparation was prepared for each submitted lymph node and was stained by the rapid Papanicolaou method. The intraoperative cytologic diagnosis was compared with the final surgical pathologic diagnoses. The overall sensitivity of intraoperative cytology was 52.5% with specificity of 100%. There were 17 false-negative cases. Of them, six nodes had isolated tumor cells, seven nodes had micrometastasis (0.2-2 mm), and four nodes had macrometastasis (>2 mm). There were no interpretive errors identified. The size of metastasis and tumor grade appeared to be significant factors in detecting metastasis by cytology. In addition, subsequent non-SLN involvement was 9% in patients with micrometastasis versus 50% in patients with macrometastasis (P < 0.05). Our study shows that the intraoperative cytologic evaluation of SLNs in breast carcinoma is a reasonably accurate method. The majority of false-negative cases were due to micrometastasis and isolated tumor cells.