Excision biopsy of breast lesions changes the pattern of lymphatic drainage.

Background: The aim was to validate the sentinel node biopsy procedure in women who had previous breast excision biopsy by means of determining the reproducibility of lymphoscintigraphy after surgery.
Methods: Twenty-five women scheduled for excision biopsy of a breast lesion were investigated. The day before surgery, (99m)Tc-labelled nanocolloid was injected into the tumour. Lymphoscintigraphy was repeated a minimum of 2 weeks after surgery.
Results: Preoperative lymphoscintigraphy visualized at least one sentinel node in all 25 women. Discrepancy in the drainage patterns after surgery was noted in 17 of 25 patients. A change in the drainage pattern in the axilla after excision biopsy was seen in 11 women. Drainage to the internal mammary chain was noted before surgery in 13 women, but only three had the same drainage pathways after excision biopsy.
Conclusion: After breast excision biopsy lymphoscintigraphy usually showed a different drainage pattern. This implies that sentinel node biopsy should be performed before excision biopsy to ensure optimal sensitivity.
(Copyright (c) 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)