The use of frozen section and immunohistochemistry for sentinel lymph node biopsy in breast cancer

Intraoperative pathologic evaluation of the sentinel lymph node (SLN) may guide immediate (synchronous) completion axillary lymph node dissection (ALND) for up to two-thirds of patients with nodal disease for breast cancer. The false-negative rates average one-third of cases, and one must be aware of false-positive results as this would result in unnecessary and morbid completion ALND. Currently, the use of immunohistochemistry (IHC) is controversial. There is no question that cytokeratin staining improves the sensitivity; however, there is no evidence that any of these "positive" cells are clinically significant and warrant therapy. Prospective randomized trials will be necessary to confirm or debunk the hypothesis that "sub- micrometastatic" disease has clinical significance.