Nonvisualization of a sentinel lymph node on lymphoscintigraphy requiring reinjection of sulfur colloid in a patient with breast cancer

Purpose: The injection techniques and use of lymphoscintigraphy for sentinel lymph node (SLN) biopsy in breast cancer patients vary. Some do not advocate routine use of lymphoscintigraphy. The purpose of this case report is to illustrate when lymphoscintigraphy should be used. Methods: At our institution, we use periareolar intradermal injections of 0.6 mCi Tc-99m sulfur colloid followed by lymphoscintigraphy with reported identification rates greater than 99%. The only patient in our series who did not have a SLN identified had presented after excisional biopsy of an upper outer quadrant cancer. We report the case of another patient who presented after excision of an upper outer quadrant invasive ductal carcinoma and had no evidence of lymphatic drainage on lymphoscintigraphy after the periareolar injections of radioisotope. Results: Additional injections of 0.4 mCi Tc-99m sulfur colloid were performed lateral to the incision in the upper outer quadrant. On lymphoscintigraphy a SLN was visualized and was subsequently successfully identified intraoperatively. Conclusion: This case report supports the value of lymphoscintigraphy for successful identification of a SLN in a patient with prior surgery. We therefore recommend imaging patients who have had prior breast surgery, particularly excisions in the upper outer quadrant.