Abstract:

Objective

The objective of this study was to define the direction， route and number of sentinel lymphatic channels （SLCs） and their relationship with sentinel lymph node （SLN） after subareolar injection of methylene blue and technetium 99m sulfur colloid （⁹ Tc^m-SC）， as well as to explore why sentinel lymph node biopsies（SLNB） produce false negative results in breast cancer patients.

Methods

⁹⁹Tc^m-SC was injected preoperatively， and methylene blue was injected by the same subareolar route just after anesthetic induction， then SLNB was carried out according to SLCs in 93 breast cancer cases （stage Ⅰ-Ⅱ）.

Results

SLCs and SLN were identified by using both methylene blue and⁹⁹Tc^m-SC in 81 cases successfully.In most cases， a single SLC exited the areola， traveled through the upper， outer quadrant and terminated at an axillary SLN.No false negative or false positive was demonstrated by pathological ananlysis of SLN which was identified according to SLCs.

Conclusions

No evidence showed that the mechanism of axillary lymph node metastasis is skip metastasis.We conclude that false negative results from SLNB seems to be associated with the technique used， which may be caused by the incomplete knowledge of the anatomical relationship between SLCs and SLN.By combining use of subareolar injection of methylene blue and⁹Tc^m-SC，SLCs and SLNs can be identified preoperatively and dissected carefully during operation.The detection rate of SLCs can be improved and the false negative rate of SLNB can be reduced.

Key words: Breast neoplasm, Sentinel lymph node biopsy, Sentinel lymphatic channels, Methylene blue, Technetium 99m sulfur colloid