Comparison of different histopathological methods for the examination of sentinel lymphnodes in breast cancer

Background: Sentinel lymphonodectomy is a new method for the classification of axillary lymphnodes in breast cancer. The optimum technique for the pat hological examination of sentinel lymphnodes (SLNs) is still under debate. Materials and Methods: Different histopathological techniques were evaluate d in order to study their diagnostic accuracy regarding the detection of me tastases in 49 SLNs of 40 breast cancer patients. Results: In single hemato xylin and eosin (HE) stained paraffin sections 18 out of 40 patients showed positive SLNs and 8 out of 40 showed positive axillary lymphnodes (ALNs). Serial sections with a spacing of 150 mu m between following sections revea led 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 the se data and detected one additional case with isolated tumor cells in the l ymphnode sinus. Conclusion: Histopathological nodal staging of SLNs should include serial sections with a spacing of 150 pm between sections as well a s immunohistochemistry. The ultrarapid-immunohistochemistry is a sensitive method for the detection of minimal metastatic disease in SLNs and can be a pplied intraoperatively.