RESUMO
It has been suggested that intraoperative dye injection of a breast cancer lesion may opacify the first [sentinal] axillary lymph node [SLN] encountered in the lymphatic pathway of this lesion and that its status could accurately reflect that of the axilla. This information would allow selective axillary dissection or sparing. Thus reducing unnecessary surgery, morbidity, and cost. Forty-eight women who were undergoing mastectomy and axillary clearance of operable breast cancer [T1-3, NO-1, MO] were investigated. Some 10 ml methylene blue dye was injected into the tumour after induction of anaesthesia. During axillary dissection the SLN, if found, was marked by a long black silk stich and then the axilla was cleared. The frequency of SLN involvement was correlated with total axillary gland involvement. The SLN was identified at operation in 40 cases [83.3%] in many cases, this necessitated extensive axillary dissection. SLN locations were at level I, 28; level II 6; level III 1. in 5 cases SLN was found during bench dissection [level not specified]. In 8 cases [16.7%] no dye was demonstrated in any gland. There was malignant axillary node involvement in 26 specimens. The SLN was involved in 21 [52.5%] [true positive] and not involved in 1 [2.5%] [false negative] all nodes were metastatic free in 14 cases [35%] [true negative]. SLN is not easily identified by methylene blue dye injection. However if found it can predict the axillary nodal status with reliable accuracy