Clinical implications of sentinel nodes outside the axilla and internal mammary chain in patients with breast cancer

Abstract

Purpose The aim of this study was to determine the incidence, location, surgical identification rate, tumor status, and clinical implications of sentinel nodes outside the axilla and internal mammary chain. Patients and Methods In 785 breast cancer patients, pre-operative lymphoscintigraphy was performed after intratumoral injection of 116 MBq ^99mTc-labeled nanocolloid (0.2 ml; 3.1 mCi). Sentinel nodes were pursued using a gamma-ray detection probe and vital blue dye. Results Lymphoscintigraphy visualized sentinel nodes outside the axilla and internal mammary chain in 91 of the 785 patients (12%). Sentinel nodes (106) were identified in 80 patients. These nodes were found in the following locations: 50 in the breast, 31 in the infraclavicular fossa, 19 between the pectoral muscles, and 6 within the supraclavicular bed. Eighteen nodes contained a metastasis (17%) and were removed from 16 patients. The treatment strategy was adjusted in 12 of them with the addition of adjuvant local or systemic therapy. Two additional patients with an unusually situated tumor-negative sentinel node were spared an axillary node dissection that would otherwise have been performed. Conclusion Unusually situated sentinel nodes were visualized in 12% of the patients. The treatment was adjusted in 18% of patients in whom these nodes were identified. J. Surg. Oncol. 2006;94:281–286.