Intraoperative assessment of sentinel nodes in breast cancer

Evaluation of Intraoperative Scrape Cytology for Sentinel Lymph Node Biopsy in Patients with Breast Cancer

The techniques for intraoperative evaluation of sentinel lymph nodes (SLNs) vary. The most common methods include frozen section, imprint cytology/touch preparation cytology, and scrape cytology (SC). The purpose of this study was to evaluate whether there is concordance between the intraoperative SC and the final pathology of SLNs in patients with breast cancer. From October 2001 to June 2005, sentinel lymph node biopsies were attempted in 181 patients with breast cancer using a combination of blue dye and radioisotope. A lymph node was considered an SLN when it was stained with blue dye, had a blue lymphatic afferent, had increased radioactivity, or was abnormal by palpation. SLNs were successfully identified in 180 patients, for an identification rate of 99.4%. Forty-five patients had positive SLNs. In 16 (35%) of those patients, the SLNs were negative intraoperatively by SC. All of the false negatives occurred in SLNs with micrometastases. Thus, SC is an excellent method for identifying macrometastases intraoperatively, but less successful for micrometastases.

Intraoperative evaluation of sentinel lymph nodes for breast carcinoma: current methodologies

Sentinel lymph node biopsy is an important new addition to the surgical management of patients with breast carcinoma. Sentinel nodes have a higher chance of containing metastases than do nonsentinel nodes. Sentinel lymph node biopsy provides an opportunity to stage breast carcinoma patients more accurately and to modify subsequent treatment. One of the most exciting current roles of sentinel lymph node biopsy is the ability to stage patients intraoperatively, allowing a one-step axillary lymph node dissection if the sentinel lymph node contains metastatic carcinoma. Currently, intraoperative evaluation of sentinel lymph nodes is performed using imprint cytology with or without rapid cytokeratin staining, frozen sectioning with or without rapid cytokeratin staining, scrape preparations, or some combination of these techniques. We review the relative strengths and weaknesses of these different methodologies. A great deal of controversy exists regarding the management of patients with metastatic breast carcinoma, particularly those patients with occult and micrometastatic disease. These issues are beyond the scope of this article.

Utility of intraoperative frozen section analysis of sentinel lymph nodes in breast cancer

BACKGROUND

Intraoperative frozen section pathologic analysis of sentinel lymph node (SLN) may guide immediate (single-stage) completion axillary dissection for patients with nodal metastases.

METHODS

The results of 203 consecutive patients undergoing SLN biopsy who had intraoperative pathology consultation between January 1998 and September 2000 were reviewed. SLN were analyzed by standard frozen section procedures. Final pathologic analysis included hematoxylin and eosin (H&E) staining of serial sections at 2-mm intervals.

RESULTS

Frozen section analysis correctly identified a positive or negative result in 185 of 203 cases (overall accuracy 91%). In 17 of 53 cases, the SLNs were negative for tumor by frozen section, but positive on permanent section analysis (sensitivity 68%). The mean size of the nodal metastases was 6.2 mm and 1.5 mm in patients found to have true positive and false negative results, respectively (P <0.003). A single false positive SLN is reported.

CONCLUSIONS

Two thirds of the patients were spared the need for reoperative axillary lymphadenectomy.