Lymphoscintigraphy in breast cancer: the value of breast lymphoscintigraphy in breast sentinel node staging.

A 28-year-old woman with an infiltrating ductal carcinoma in the upper outer quadrant of the left breast diagnosed by excisional biopsy underwent lumpectomy, intraoperative lymphatic mapping, and sentinel node dissection. This was followed by an immediate completion axillary node dissection using a hand-held gamma probe and isosulfan blue to map the lymphatics. Preoperative breast lymphoscintigraphy showed drainage into the axilla and an apparent area of radiocolloid accumulation in the inferior hemisphere of the left breast. Because our protocol called only for removal of axillary sentinel nodes, the inferior hemisphere radiocolloid accumulation was not removed. The patient did not complete local regional therapy with breast irradiation and developed a mass in the inferior hemisphere of the left breast, which on biopsy was shown to be metastatic breast cancer in an intramammary lymph node. This case illustrates the potential value of breast lymphoscintograms to identify unusual sites of lymphatic drainage that may prove to be clinically relevant.