Abstract:

Objective

To explore a more rational pathological detection method for micrometastasis of sentinel lymph nodes （ SLNs） and its clinical significance.

Methods

Fifty women with breast cancer were included.109 SLNs of the 50 patients were identified negative by standard hematoxylin and eosin （HE） staining examination carried out on initial levels.All SLNs were step sectioned （SS） atl00μm interval and for each level both HE stain examination and immunohistochemical detection with AE1/AE3 were performed.Then different detection methods were analyzed.

Results

In the 50 negative SLN patients， 13 and 17 cases were upstaged in node status by using SS-HE method and combined IHC method separately， therefore the positive detecting rate was increased by 26% and 34% ， respectively.Four cases were upstaged in node status via using SS combined with IHC method， the positive detecting rate was increased by 8% （P﹥0.05）.In all 1166 slides， 57 slides （4.9% ） were abnormal by SS， and 28 （2.4% ） slides were abnormal by SS combined with IHC （ P﹤0.05）.The rate of detection of MMs in 100-， 200-， 300-，400-， and 500 μm intervals was 26% ，20% ， 20% ， 16% ， and 14% by SS with HE stain respectively， and 34% ， 32% ， 30% ， 32% ， and 30% by the method of SS combined with IHC.

Conclusions

SS could significantly increase the detection of occult tumor deposits in negative SLN with routinely histological exam； IHC could increase the detection of abnormal slides； SS in different intervals does not add significance.

Key words: Sentinel lymph node, Breast neoplasms, Micrometastasis, Step section, Immunohistochemistry