Lymphatic stream from a breast tumor to a sentinel node in the parasternal node basin: Consideration of two cases with internal mammary node metastases

Prior to worldwide acceptance of the sentinel lymph node concept, internal mammary node dissection was regarded as unnecessary for diagnosis of breast cancer. More recently, the impact of internal mammary nodes dissection on the survival of breast cancer patients has come under scrutiny. We have encountered important breast cancer cases involving lymphatic streams that go from the tumor to both the internal mammary chain and axillary node basin simultaneously. Moreover, a lymphatic stream was found to go from the breast tumor to the internal mammary chain via intra-mammary gland lymph nodes. These cases indicate the dual importance of internal mammary sentinel node dissection as well as axillary sentinel node dissection.