Histopathologic Examination of the Sentinel Lymph Nodes

Application of Real-time Elastography Ultrasound in the Diagnosis of Axillary Lymph Node Metastasis in Breast Cancer Patients

The pathological status of axillary lymph nodes (ALN) plays a critical role in the staging and treatment of patients with breast cancer. Therefore, differential diagnosis of metastatic ALN is highly desirable in the clinic. We used real-time elastography (RTE) and gray-scale ultrasound to generate a new scoring system for determining ALN status and estimate their performance of this system. Ninety-seven ALNs were examined by both gray-scale ultrasound and RTE. The performance of gray-scale ultrasound was evaluated by the sum of scores according to its features. RTE images were determined by a modulated scoring system based on the percentage and distribution of hypoechoic cortex regions in the ALNs. Strain ratio was also calculated. Diagnostic performance was obtained by receiver operating characteristic curve analysis with pathologic findings used as the reference standard. The sensitivity, specificity and accuracy were 92%, 73% and 83%, respectively, for gray-scale ultrasound; 78%, 93%, 86%, respectively, for RTE; 88%, 96% and 92%, respectively, for the combined evaluation (AUC = 0.963), and 87%, 76% and 81%, respectively, for strain ratio. Gray-scale ultrasonography had a better sensitivity than RTE (92% vs 78%, P = 0.039), while the specificity for RTE was superior to that of gray-scale ultrasonography (93% vs 73%, P = 0.012). In conclusion, RTE showed a high specificity for evaluating the ALN status and may improve the diagnostic accuracy when combined with gray-scale ultrasound.

Intraoperative Frozen Section Evaluation of Sentinel Lymph Nodes in Breast Carcinoma: Single-Institution Indian Experience

Sentinel lymph node biopsy is an established way of predicting axillary nodal metastasis in early breast cancer. Intraoperative frozen sections (FS) of sentinel lymph nodes (SLNs) can be used to detect metastatic disease, allowing immediate axillary lymph node dissection. The purpose of this study was to evaluate the accuracy of intraoperative frozen sections in evaluation of sentinel lymph nodes in cases of breast cancer. Between March 2006 and August 2010, a total of 164 patients with clinically node-negative operable breast cancer were subjected to sentinel lymph node biopsy of axillary lymph nodes using preoperative peritumoral injection of radioactive colloid and methylene blue. Intraoperative identification of sentinel nodes was done using a handheld gamma probe and identification of blue-stained nodes. The nodes were sent for frozen section examination. The results of frozen section were compared with the final histopathology. Out of the 164 cases, metastases were detected in SLN by frozen section in 38 cases. There were three false-negative cases (all showing micrometastasis on final histopathology). FS had sensitivity of 92.6 %, specificity of 100 %, and overall accuracy of 98.1 %. The positive predictive value was 100 %, and the negative predictive value was 97.6 %. FS for diagnosis of metastasis of SLNs is reliable. Patients with negative SLNs by the FS diagnosis can avoid reoperation for axillary lymph node dissection. However, FS may fail to detect micrometastases, especially in cases with small tumors.

Histologic evaluation of sentinel and non-sentinel axillary lymph nodes in breast cancer by multilevel sectioning and predictors of non-sentinel metastasis

Sentinel lymph node (SLN) provides accurate nodal staging for breast cancer. This technique has been introduced in Siriraj Hospital since 1998. The goal of this study is to assess its accuracy in predicting the state of the axilla, and compare the results of standard examination and multilevel sectioning. A retrospective analysis of 195 breast cancer patients who underwent both SLN biopsy (using dye alone as the lymphatic mapping) and axillary node dissection during 1998-2002 were analyzed. All slides including SLNs and the non-SLNs (NSLNs) were reviewed and multilevel study was performed on all SLNs and NSLNs [four levels of hematoxylin-eosin (HE) at 200 µm interval and keratin stains on the first and fourth levels]. Of 195 patients, 30% of cases were SLN-positive (32 NSLN-positive and 27 NSLN-negative). Additional study could detect positive axillary nodes 10.8% (4 SLN-positive and 5 NSLN-positive) more than standard HE stain. The false negative rate increased from 20.3% to 24.1%. The concordance between SLN and NSLN statuses was 89.7%. The sensitivity was 75.9%. By multivariate analysis, the significant predictors for axillary node metastasis were tumor size of more than 2.2 cm, histologic type of invasive ductal carcinoma (IDC), not otherwise specified (NOS) and lymphovascular invasion (LVI). By univariable analysis, the significant predictors of NSLN metastasis after positive-SLN were outer location of the tumor, LVI and perinodal extension. In conclusion, use of multilevel and immunohistochemistry increased detection of positive-SLNs. Caution should be kept in accepting SLN biopsy using peritumoral dye technique alone as the procedure for staging due to a high false-negative rate. The concordance rate of 89.7% confirmed the reliability of SLN. Outer location of tumor, LVI and perinodal extension is significant predictors of positive-NSLN after positive-SLN.

Diagnostic value of intraoperative histopathological examination of the sentinel nodes in breast cancer and skin melanoma-Preliminary results of single centre retrospective study

OBJECTIVE

Intraoperative histopatological examination of the sentinel nodes enables selection of patients who need dissection of the regional lymphatic system during the same operation. The aim of this study is to evaluate the diagnostic value of intraoperative histopathological examination of the sentinel nodes in breast cancer and skin melanoma. Intraoperative histopathology of the sentinel nodes as a diagnostic method is used in patients with melanoma and breast cancer. Recent studies have proved it to be an effective method for evaluating the nodes in the final histopathology. Intraoperative histopathological examination of the sentinel nodes is not performed routinely and there is no clear position on this issue. In this paper we try to prove that intraoperative test gives patients the simultaneous benefits of removal of regional lymph nodes metastases and earlier initiation of adjuvant therapy.

METHODS

The study comprises 137 patients with breast cancer and 35 patients with malignant skin melanoma. Sentinel nodes were intraoperatively sectioned and examined by means of the imprint method and frozen section evaluation. The patients with positive sentinel nodes underwent immediate dissection of regional lymph nodes. Those with negative sentinel nodes diagnosed in the intraoperative examination, but positive in final pathologic results, underwent subsequent dissection of regional lymph nodes.

RESULTS

60 sentinel lymph nodes were found in 35 patients with skin melanoma. In 3 patients, 3 sentinel lymph nodes were false negative in the intraoperative histopathological examination. No false positive sentinel lymph nodes were found. 249 sentinel lymph nodes were found in the intraoperative histopathological examination in 137 patients with breast cancer. There were no false positive sentinel nodes, but there were 7 false negative sentinel nodes. In this study, only 5 (3.6%) patients with breast cancer and 3 (8.5%) patients with skin melanoma required another regional operation.

CONCLUSION

The method of intraoperative histopathological evaluation of the sentinel nodes enables identification of metastases in these lymph nodes and gives a possibility to carry out a one-step regional lymphadenectomy and start the adjuvant therapy earlier.

Intraoperative imprint cytology for breast cancer sentinel nodes: is it worth it?

BACKGROUND

Re-operative surgery is stressful for patients and is an additional burden to an already stretched public health system. Intraoperative confirmation of breast cancer metastases in sentinel lymph nodes (SLNs) provides the necessary information for the surgeon to proceed with immediate axillary dissection, avoiding the need for a second operation, its associated cost, morbidity and adjuvant treatment delays. Our challenge was to implement a technique that was rapid, inexpensive and had a negligible false positive rate. The aim of this study was to determine whether touch imprint cytology (TIC) could reduce returns to theatre without compromising patient safety and pathology department and operating theatre efficiency.

METHODS

Intraoperative TIC was performed on bisected SLNs from 134 patients. Post-operatively, specimens were examined as haematoxylin and eosin-stained, paraffin-embedded 2-mm sections. Further sectioning and immunohistochemisty was performed on negative SLNs.

RESULTS

The sensitivity of TIC for metastases was 23.8%, the specificity was 100% and the accuracy was 76.1%. Ten patients with macrometastases and none with micrometastastes were detected intraoperatively. The sensitivity of TIC for detecting macrometastases was 34.5%, the accuracy was 78.4% and the specificity was 100%.

CONCLUSION

Ten patients avoided a subsequent surgery. The technique caused no theatre delays and the minimal cost was compensated for by the avoidance of a second procedure for a third of patients who definitively required axillary clearance. No patients had an unnecessary axillary clearance and no patients with micrometastases or isolated tumour cells were subjected to an immediate axillary clearance. It would be justifiable to continue this simple, low-cost and non-disruptive approach.

Lobular and non-lobular breast cancers differ regarding axillary lymph node metastasis: a cross-sectional study on 4,292 consecutive patients

Invasive lobular carcinoma (ILC) accounts for 8-14% of all breast cancers and carries distinct prognostic and biologic implications. The goal of our study was to investigate the impact of lobular histology on axillary lymph node (ALN) involvement. This is a cross-sectional study of 4,292 consecutive patients surgically treated for breast carcinoma at the University Hospitals Leuven. Logistic regression analysis was used to relate ILC to lymph node involvement while controlling for the following clinicopathologic features: tumor size, multifocal disease, tumor grade, lobular subtype and the combined steroid, and Her-2 status. Odds ratios (ORs) and 95% confidence intervals (CIS) were computed. A subgroup analysis was performed for patients that underwent a sentinel lymph node (SLN) procedure. The observed incidence of ILC was 13%. ILCs were larger, were more often grade II, multifocal, steroid receptor positive and Her-2 negative, and tended to be present in older patients. Incidence of ALN involvement was 42.0% for ILCs versus 38.3% for other tumors (OR 1.17, 95% CI 0.97-1.40). For the SLN subgroup, ILCs were less often ALN positive than non-ILCs (20.5% versus 28.3%, OR 0.66, 95% CI: 0.41-1.00). In the multivariable analysis, the lobular subtype was identified as less likely to have ALN involvement (adjusted OR 0.66, 95% CI 0.53-0.82). The analysis for the SLN subgroup showed comparable results (adjusted OR 0.49, 95% CI 0.30-0.78). This study has demonstrated that the lobular subtype is an independent predictor of lymph node involvement with ILC having a lower incidence of involved lymph nodes. The mildly higher incidence of ALN metastasis in lobular cancers in univariable analysis is not due to the lobular subtype, but due to confounding factors that interact with lymph node involvement.

Identification and biologic significance of micrometastases in axillary lymph nodes in patients with invasive breast cancer

CONTEXT

The presence or absence of metastases in axillary lymph nodes is one of the most important prognostic factors for patients with breast cancer. During the past decade sentinel lymph node (SLN) biopsy has been increasingly adopted as a minimally invasive staging alternative to complete axillary node dissection.

OBJECTIVE

Sentinel lymph nodes are more likely to contain metastases than non-SLNs. In routine clinical practice SLNs are assessed by diverse methodologies including multiple sectioning, immunohistochemical staining, and molecular diagnostic tests. Despite the lack of standard histopathologic protocols during the years detailed evaluation of SLNs has resulted in an increased detection of small (micro) metastases.

DATA SOURCES

Breast cancer with micrometastases constitutes a heterogenous group of tumors with variable clinical outcome regarding the risk of additional metastases in the remaining axillary lymph nodes and to patients' survival.

CONCLUSION

The clinical significance of micrometastases has been subject to great controversy in patients with breast cancer. In this review we highlight controversies regarding micrometastases especially in relation to SLNs.

[Sentinel node biopsy in breast cancer: pathological analysis and interpretation]

This overview examines how the introduction of sentinel lymph node biopsy (SLNB) has changed the pathological staging of breast cancer. The more intensive analysis of the sentinel lymph nodes (gross slicing, step sections, immunohistological or molecular analysis) has lead to stage shifting in breast cancer. Regarding the rate of up-staging by positive results of SLNB, there are significant differences between institutes, some method-related, some related to the interpretation of results. Methodological differences should be reduced by means of reliable guidelines with the goal of systematically identifying metastases of a particular size (a macrometastasis over 2 mm being the minimum criterion). The next review of the TNM classification should result in a reduction in interobserver variability as a result of better definitions of staging categories for isolated tumor cells and micrometastases. In addition, a staging category is expected for metastases which have been identified by calibrated quantitative molecular tests only and which are larger than isolated tumors. Even in settings where nodal staging by SLNB is based on molecular tests at least a proportion of the lymph node should be investigated histologically.

Immunohistochemistry on frozen section of sentinel lymph nodes in breast cancer with improved morphology and blocking of endogenous peroxidase

Sentinel lymph node biopsy in the management of patients with breast cancer is the clinical practice. Peroperative examination means that more patients can be treated in a 1-step procedure. The addition of immunohistochemistry to frozen section slides improves the detection rate of especially micrometastasis. We present a novel method for immunohistochemical staining on a frozen section material that gives better morphology and blocks endogenous peroxidase sufficiently.

Minimal disease in sentinel nodes

Isolated tumor cells and micrometastases represent low-volume or minimal disease in the regional lymph nodes of breast cancer patients as compared to macrometastases. Sentinel lymph node biopsy is a functional selection and removal of the most likely site of regional metastasis, and gives pathologists the opportunity to concentrate detection techniques on a limited number of lymph nodes. Consequently, more lesions belonging in the two mentioned staging categories are discovered in sentinel lymph nodes. Despite some publications contradicting stochastic models of breast cancer, micrometastases seem to reflect a prognosis intermediate between the node-negative and macrometastatic nodal status, and they also reflect a risk of non-sentinel node involvement slightly higher than that associated with a node-negative status. Data are more contradictory as concerns isolated tumor cells. This minireview summarizes the definitions, their inconsistencies, pathological protocols aiming at the detection of minimal nodal disease, the prognostic impact and non-sentinel node involvement related risk of such nodal lesions, and their therapeutic consequences.

Sentinel Node Positivity Rates With and Without Frozen Section for Breast Cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) is used to detect breast cancer axillary metastases. Some surgeons send the sentinel lymph node (SLN) for intraoperative frozen section (FS) to minimize delayed axillary dissections. There has been concern that FS may discard nodal tissue and thus underdiagnose small metastases. This study examines whether evaluation of SLN by FS increases the false-negative rate of SLNB.

METHODS

A retrospective analysis of SLNB from 659 patients was conducted to determine the frequency of node positivity among SLNB subjected to both FS and permanent section (PS) versus PS alone. Statistical analysis was performed by the chi(2) square test, and a logistic regression model was applied to estimate the effect of final node positivity between the two groups.

RESULTS

FS was performed in 327 patients and PS was performed in all 659 patients. Among patients undergoing both FS and PS (n = 327), the final node positivity rate was 33.0% compared with 19.6% among patients undergoing PS alone (n = 332). After adjustment for patient age, tumor diameter, grade, and hormone receptor status in a multivariate logistic regression model, there remained an increased likelihood of final node positivity for patients undergoing both procedures relative to PS alone (adjusted odds ratio, 2.1; 95% confidence interval, 1.3-3.6; P = .005).

CONCLUSIONS

There was a higher rate of SLN positivity in specimens evaluated by both FS and PS. Therefore, evaluating SLN by FS does not underdiagnose small metastases nor produce a higher false-negative rate. Intraoperative FS offers the advantage of less delayed axillary dissections.

Factors affecting false-negative breast sentinel node biopsy in Chinese patients

BACKGROUND

The objective of the research was to validate our results on sentinel lymph node biopsy (SLNB) and to determine factors affecting false-negative (FN) rates of SLNB in Chinese patients with invasive breast cancers.

METHODS

A retrospective study of patients with clinically node-negative invasive breast cancer was carried out from May 1999 to April 2006. A combination of radioisotope (99m)technetium(Tc)-albumin sulfur colloid and Patent Blue V dye was used to identify the sentinel lymph node. Sentinel lymph node biopsy was followed by standard level I and II axillary dissection in all patients. Various clinicopathologic variables were analysed to determine factors associated with FN SLNB.

RESULTS

Three hundred and sixty-five Chinese patients received SLNB consecutively during the study period. Seventy-eight patients with neoadjuvant chemotherapy and 56 patients with in situ carcinoma were excluded. A total of 231 patients were studied. Sentinel lymph nodes were identified in 221 patients (95.7%). There were 10 FN, resulting in a FN rate of 12.5% and accuracy rate of 95.5%. Only the number of sentinel lymph node harvested was found to be a significant factor affecting FN rates on univariate (P < 0.009) and multivariate logistic regression (odds ratio: 2.65; 95% confidence interval: 2.57-2.73; P < 0.000).

CONCLUSIONS

In Chinese women, after this retrospective analysis of available findings, at least should sentinel nodes should be removed to reduce risk of false negativity.

Pathological Evaluation of Sentinel Lymph Nodes

The sentinel lymph nodes are the most likely site of nodal metastasis. Their focused analysis results in upstaging cancers, although the extra yield from a more intensive work-up is generally dominated by micrometastases and isolated tumor cells. Nodal staging is generally done to reflect systemic spread of solid tumors and guide treatment accordingly. However, in general, the two processes of haematogenous and lymphogenic spread are not causally interrelated, and the extrapolation from low-volume nodal involvement to systemic involvement and therapeutic consequences of this extrapolation are still under investigation.