Sentinel lymph node biopsy in primary breast cancer: trust the radiolabeled colloid method and avoid unnecessary procedures

Background With regard to the sentinel lymph node (SLN) procedure in breast cancer, the study analyzed the impact of discrepancies between the number of clinically and histologically identified SLN, the impact of removing additional non-hot/non-blue but clinically conspicuous lymph nodes (LN), and whether the application of blue dye for mapping is necessary. Methods We analyzed 391 SLN procedures in which 928 SLN were removed. In all cases, radiolabeled colloid and blue dye were used for SLN mapping. Results In 60 cases (15.3%), additional LN that were not identified by the surgeon were found by histological examination. In 22 cases (5.3%), tissue which clinically resembled an SLN but was histologically connective tissue, was removed. In 76 cases (19.4%), 133 non-hot/non-blue but clinically conspicuous LN were removed. These additionally removed LN, however, did not alter the axillary staging. In 50.8% of the cases ( n = 471), the SLN were marked only by radiolabeled colloid. In 27 cases (2.9%), the surgeon identified the LN through blue coloration alone; however, in all of the latter cases, these SLN were not deciding for axillary staging. Conclusion The mapping agents may accumulate in axillary tissue and mimic the existence of an SLN. The radiolabeled colloid method alone gives excellent mapping results. The additional application of blue dye is avoidable. Exact surgical preparation enables removal of the SLN only and avoids removal of LN-containing adjacent tissue. The removal of further clinically identifiable enlarged non-hot LN should only be done if there is strong suspicion of metastatic involvement.