Axillary sentinel lymph node examination in breast carcinoma

Objective.-To evaluate whether the type of pathologic examination of breast sentinel nodes (frozen section, step sections, and immunoperoxidase staini ng) results in different percentages of nodes positive for metastatic disea se. Design.-Twenty-eight consecutive patients with breast sentinel node biopsie s were evaluated by step-sectioning the sentinel node(s) along with perform ing immunoperoxidase stains for low-molecular-weight cytokeratin and epithe lial membrane antigen. Setting and Participants.-The patients were from a university hospital and large private hospital. Main Outcome Measures.-The results of the step sections and immunoperoxidas e stains were compared with routine examination, that is, intraoperative fr ozen section along with a single hematoxylin-eosin slide. Results.-Nine cases were positive by routine evaluation, 10 by step section s, and 11 by immunoperoxidase staining. Conclusions.-The large, multi-institutional studies of sentinel node utilit y must take into account the surgical pathology methods used to evaluate th ese specimens so that uniform techniques, which reliably predict the status of the axillary nodes, can be instituted at all institutions that use this procedure.