Comparison of different histopathological methods for the examination of sentinel lymph nodes in breast cancer.

BACKGROUND: Sentinel lymphonodectomy is a new method for the classification of axillary lymph nodes in breast cancer. The optimum technique for the pathological examination of sentinel lymph nodes (SLNs) is still under debate.

MATERIALS AND METHODS: Different histopathological techniques were evaluated in order to study their diagnostic accuracy regarding the detection of metastases in 49 SLNs of 40 breast cancer patients.

RESULTS: In single hematoxylin and eosin (HE) stained paraffin sections 18 out of 40 patients showed positive SLNs and 8 out of 40 showed positive axillary lymph nodes (ALNs). Serial sections with a spacing of 150 microns between following sections revealed an additional 4 and 5 cases with positive SLNs and ALNs, respectively. Single HE frozen sections showed 11 tumor positive SLNs among 25 patients. The ultrarapid-immunohistochemistry on single frozen sections confirmed these data and detected one additional case with isolated tumor cells in the lymph node sinus.

CONCLUSION: Histopathological nodal staging of SLNs should include serial sections with a spacing of 150 microns between sections as well as immunohistochemistry. The ultrarapid-immunohistochemistry is a sensitive method for the detection of minimal metastatic disease in SLNs and can be applied intraoperatively.