Pathological validation and significance of micrometastasis in sentinel nodes in primary breast cancer

In embracing a multidisciplinary approach to the management of patients wit h sentinel node biopsy in breast cancer, the pathologist task is to screen sentinel nodes for possible metastasis. The consequences of missing sentine l node micrometastasis can directly influence treatment strategies, and thi s screening therefore has to be performed with more attention than usual. T here is presently great diversity in the histopathological work-up of senti nel nodes, with many centres employing additional techniques such as immuno histochemistry, reverse transcription polymerase chain reaction or flow cyt ometry in addition to routine haematoxylin and eosin staining. In this revi ew, we address the pathological validation and significance of micrometasta sis in sentinel node biopsy in primary breast cancer.