Enlarged lymph node

Why watch an enlarged lymph node in the breast if the mammogram was negative?

[Cleveland Clinic]

Dear girls8:  Lymph nodes are often present in the breast tissue.  The normal function of a lymph node is to act as filters.  The normal size of a lymph node ranges from a couple of millimeters to about a centimeter.  When there is infection or inflammation, a lymph node may enlarge.  The purpose of watching an enlarged lymph node in the setting of a negative mammogram is to ensure that the lymph node is not continuing to grow, which may be cause to investigate further.