Sentinel lymph node biopsy in breast cancer: creating controversy and defining new standards

Sentinel lymph node (SLN) biopsy is an exciting and promising new addition to surgical management and pathologic evaluation of breast cancer. Sentinel nodes are more likely to contain metastases than nonsentinel nodes providing an opportunity to more accurately stage breast cancer patients. In the future, surgical management of the axilla may be approached as a staged procedure, perhaps eliminating axillary dissection in SLN-negative patients, should clinical trials demonstrate the safety of this approach. The advent of SLN biopsy has propelled an old question back to the forefront of clinical investigation: do occult metastases in lymph nodes have prognostic, predictive, and clinical significance? This article provides one opinion and a review on the pathology and future of SLN biopsy in breast cancer. Practicing pathologists will need to stay abreast of the issues and facts in order to participate in the debate and shape the future of pathologic management of sentinel nodes.