Objective: Sentinel lymph node (SLN) localization in breast cancer allows biopsy of directly tumor drained lymph nodes. The objective was to study the association of tumor and SLN localization.
Patients and methods: SLN was identified in 39 (81%) of 48 patients with histologically proven breast cancer, clinically and sonographically unsuspected axillary lymph nodes after peritumoral application of 40-50 Mbq 99mTc-Nanocolloid. Patients age, tumor size and localization, histology and localization of the SLN as well as removed axillary lymph nodes were analyzed.
Results: Axillary lymph node metastases were found in 11 (28%) of 39 patients. Involvement of the SLN was confirmed by intraoperative frozen sections (n = 9) and paraffin embedded histology (n = 1). One (9%) patient with a positive node revealed a false-negative SLN. In 24 patients with a tumor in the lateral hemisphere of the breast the SLN were identified in the ipsilateral axilla. In 6 (40%) of 15 patients with a central or medial localized tumor the SLN was observed infraclavicular (n = 3), parasternal (n = 2) or in the contralateral axilla (n = 1). In the latter one the SLN of the contralateral axilla showed metastases, whereas the simultaneous SLN and all removed lymph nodes of the ipsilateral axilla were not involved. More than one SLN were found in 12 (31%) of the 39 cases.
Conclusion: A correlation between tumor localization and localization of the SLN is suggested, but the lymph drainage seems more variable in cases of medial tumor size. Using blue dye for map of extraaxillary SLN seems inappropriate. Currently the diagnostic and therapeutic impact of the detection of extraaxillary SLN is still unclear.