Bilateral axillary and internal mammary drainage in breast cancer without prior surgery during sentinel node mapping.

Lymphatic drainage outside the ipsilateral axilla in breast cancer is discovered in as many as 25% of all sentinel lymph node procedures and it is evidenced by lymphoscintigraphy. Contralateral axillary drainage is a rare clinical situation, mostly if there is not prior breast surgery, but this situation is extremely exceptional if we also found internal mammary chain drainage. We have not found such a case published in literature.