ročník 11,2003 č.4
Abstrakta

Sentinel nodes outside the axilla

E. Nieweg, Susanne H. Estourgie, Renato A. Valdés Olmos, Emiel J. Th. Rutgers, Bin B.R. Kroon

The Netherlands Cancer Institute,
Antoni van Leeuwenhoek Hospital,
Amsterdam, the Netherlands

Introduction

The first aim of this study was to describe the lymphatic drainage patterns from the five 'quadrants' of the breast. The second aim was to determine the incidence, location, identification rate and relevance of extra-axillary sentinel nodes in breast cancer patients.

Methods

From January 1999 to May 2002, 600 sentinel node procedures were performed of which 146 patients had a non-palpable tumor. Preoperative lymphoscintigraphy was performed after injection of a mean dose of 107.7 MBq (2.8 mCi) 99mTc-nanocolloid into the tumor in a volume of 0.2 ml. The sentinel node was surgically identified with the aid of patent blue dye (1.0 ml, intratumoral injection) and a gamma-ray detection probe. Exploration of the axilla was always performed. Extra-axillary basins were only explored in case of lymphoscintigraphic visualization.

Results

Drainage to the axilla from the upper outer quadrant, upper inner quadrant, lower outer quadrant, lower inner quadrant and center was observed in 95.8%, 93.1%, 97.7%, 88.0% and 100% of the patients respectively. A sentinel node in the internal mammary chain region was seen in 10.4%, 32.4%, 29.5%, 52.0% and 23.7% respectively. Both palpable and non-palpable lesions drain towards the internal mammary chain, although the latter more frequently (p=0.001), regardless of the quadrant. Drainage was occasionally observed to supraclavicular, infraclavicular, interpectoral and intramammary sentinel nodes.
A sentinel node in at least one extra-axillary basin was depicted in 183/600 procedures (31%). Visualized internal mammary chain nodes could be harvested in 111/132 cases (84%) and contained metastasis in 18/111 (16%). Other visualized extra-axillary sentinel nodes were excised in 61/81 (75%) and harbored metastasis in 12 of these procedures (20%). In 15/153 (10%), the extra-axillary sentinel nodes was tumor-positive while the axilla was tumor-free. There was a change in the therapeutic management in 31/153 patients (20%). If preoperative lymphoscintigraphy had been omitted, a tumor-positive sentinel node would have been missed in 2.5% of all 600 patients.

Conclusion

From each quadrant, a breast cancer may drain to sentinel nodes in various locations. The incidence and identification rate of extra-axillary sentinel nodes was 31% and 84% respectively. Upstaging was achieved in 10% of the patients with a visualized extra-axillary sentinel node. Management changed in 20%. Sentinel nodes outside the axilla are more commonly seen in non-palpable breast cancer.