Intraoperative sentinel lymph node evaluation: Optimizing surgical pathology practices in an era of changing clinical management

• Published in: Annals of diagnostic pathology Vol. 33; pp. 45 - 50
• Main Authors: Compton, Margaret L., Sweeting, Raeshell S., Reisenbichler, Emily S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2018
• Subjects: Axilla; Breast; Intraoperative evaluation; Sentinel lymph node; Surgical pathology; Breast; Axilla; Sentinel lymph node; Intraoperative evaluation; Surgical pathology
• ISSN: 1092-9134; 1532-8198
• DOI: 10.1016/j.anndiagpath.2017.12.003

Axillary lymph node status is an independent prognostic indicator in breast cancer. Intraoperative identification of metastatic carcinoma in sentinel lymph nodes may allow for concurrent axillary lymph node dissection at the time of primary tumor excision. A retrospective review of patients undergoing primary breast cancer excision with sentinel lymph node sampling was performed. Sensitivity and specificity of imprint cytology (touch prep) with and without the incorporation of gross evaluation was determined using permanent section results as the gold standard. Five hundred sixteen lymph nodes were analyzed by imprint cytology in 213 patients, and 203 lymph nodes were analyzed in 74 patients incorporating gross examination. Sensitivity and specificity for the detection of macrometastases by touch prep alone were 60% and 99% respectively with 4 patients undergoing same-day axillary dissection for only micrometastatic disease. False negative causes included lack of transfer of malignant cells in 8 cases and misinterpretation of tumor cells in 6 cases. Incorporating gross examination in the modified protocol resulted in reduced sensitivity of 38%, but achieved the desired 100% specificity and positive predictive value. Imprint cytology alone did not reliably distinguish between micro- and macrometastatic disease. Gross assessment combined with imprint cytology allows for improved assessment of volume of axillary disease, but is an insensitive technique. •Surgical management of the axilla in breast cancer has changed due to Z0011.•Intraoperative methods must be able to distinguish micro- from macrometastases.•Imprint cytology alone does not determine the size of the metastatic focus.•Gross exam plus cytology is highly specific but insensitive for macrometastases.