Breast Cancer Clarification

I need help on coding for Breast cancer when it comes to staging. My doctor documents:

Breast Cancer Left nipple - Stage IIIB - T4 N1 M0

I know the N stands for the nodes. And the M stands for metastasis. My question is, does the doctor need to state which node and is that considered mets to the lymph nodes? Meaning if it was the axillary node would I code 196.3? Or do I not code anything at all because that is for staging purposes and does not mean a true metastasis?

174.0 & 196.3

or

174.0

Thank you,
Lydia

Breast Cancer Clarification