Typical and atypical lymphatic flows in breast carcinoma

The study of sentinel lymph node has greatly increased the knowledge about lymphatic drainage in breast cancer.

The experience of 181 patients operated for breast carcinoma in the last two years, of which 70 undergoing SLN biopsy, allowed us to highlight some peculiarities of lymphatic drainage of the breast and led us to physiological and pathological considerations about lymphatic flow in patients for breast carcinoma. We studied patients undergoing lymphoscintigraphic mapping with SLN biopsy who were candidates for breast cancer surgery.

Searching for SLN's location, we found that in 88.6% cases the SLN was at level I, in 8.6% it was at level II, in no case it was at level III and in 2.8% we found lymphatic drainage to the contralateral axilla.

Thanks to this dynamic study we were able to highlight a preferential subcutaneous lymphatic path from the breast parenchyma reaching the contralateral axilla, crossing anteriorly the thorax. Literature review showed CAM incidence ranges from 3.6% to 6% and can be caused by occult primary cancer of the contralateral breast, contralateral spread of breast cancer and presence of another kind of tumor.

The presence of contralateral axillary metastasis, although known, allowed us to scintigrafically document (for the first time) the pathway of an alternative lymph flow and to suppose the possible causes. Thanks to this observation, considerations can be drawn about clinical, pathophysiological and oncological implications, with an impact on post-operative follow-up.