A lymph node “lighting up” means it’s the “sentinel” node—one of the first in the chain to which malignancy CAN spread IF there’s spread. Doesn’t mean it contains malignant cells, however (in most cases it doesn’t).Was the node removed and/or biopsied? Sure hope so. Chances are it was not malignant. If it was, then the diagnosis of DCIS changes to invasive ductal carcinoma (IDC) and is treated accordingly (usually with at least radiation; and endocrine therapy if hormone-receptor-positive; chemo is rare in such an instance).
