What does it mean when a cancerous leaking lymph node is found during breast cancer surgery?

Cancerous leaking lymph node is not a correct medical term. You probably meant metastasized lymph node. When breast cancer cells are detected in the lymph nodes the breast cancer has been spreading and surgery alone is not enough. Patient will need adjuvant therapy either with hormone or chemo or radiation therapy.

Agree with Dr. He. If cancer is found in lymph node, it requires additional treatment. Depending on the number of nodes involved, the tumor may still be curable.