Patients with documented axillary metastases (Stage II breast cancer) will undergo subdermal injection of technetium sulfur colloid (TSC) into the ipsilateral upper extremity approximately 3 hours before surgery.

At the time of surgery, each patient will undergo a subareolar injection of isosulfan blue dye into the ipsilateral breast as routinely performed during a sentinel lymph node mapping for breast cancer. The surgeon will then perform an axillary lymph node dissection in the usual, routine manner. The above differs from standard of care in that patients scheduled for an upfront axillary dissection do not routinely undergo sentinel lymph node mapping- therefore these patients would not normally get any isotope or TSC injections since they already need an ALND. Second, standard sentinel lymph node mapping involves injection of TSC into the affected breast the day prior to surgery or 3 hours before surgery versus injection of TSC into the ipsilateral upper extremity. The protocol specifies "day of" mapping for patient convenience.