The anatomy of lymphatic drainage of the breast

A point of debate in lymphatic mapping concerns the site where the radioactive and colored tracer fluids should be administered in breast cancer patients. One of the main reasons for this controversy is lack of sufficient knowledge of the anatomy and physiology of the lymphatic system of the breast. This article describes elements of the anatomy of the lymphatic system of the breast with references to many historical studies. Aspects that may contribute to the discussion about the injection site are also presented. Tracer administration at the primary lesion site reflects lymphatic drainage of the breast tumor. Intradermal tracer administration more frequently visualizes a lymphatic channel on the lymphoscintigraphy images at the expense of visualizing extra-axillary sentinel lymph nodes.