[Detailed pathological examination of the sentinel lymph nodes in order to detect micrometastases: no clinical relevance in patients with breast cancer].

Staging of the axillary lymph nodes yields important prognostic information in patients with breast cancer. The characteristics of the primary tumour are more significant for prognosis if only micrometastases (diameter < or = 2.0 mm) are found. For staging purposes and to estimate the prognosis, pathological examination of axillary lymph nodes therefore need not be focused on the detection of micrometastases. Sentinel lymph node biopsy is increasingly being used as an alternate staging method and to determine the indication for axillary lymph node dissection. To reduce the risk of overlooking lymph node metastasis, the sentinel node is being more thoroughly investigated, resulting in the finding of micrometastases in 10-20% of sentinel node negative patients. The sentinel node tumour load correlates with the chance of detecting more metastases in the axilla: an average of 18% for micrometastases, 12% for submicrometastases (diameter < or = 0.2 mm). However, if detailed pathological examination of the sentinel node is omitted, this would result in a low false-negative percentage (1.1-2.5% of all patients undergoing a sentinel node examination), which is less than the percentage false negatives in the sentinel lymph node procedure itself (3.2% on average). Hence, the benefit of detailed pathologic examination with step sectioning and the application of immunohistochemical staining may be doubted.