Nonvisualization of Axillary Sentinel Node During Lymphoscintigraphy: Is There a Pathologic Significance in Breast Cancer?

The aim of this study was to define the factors associated with nonvisualization of a sentinel node (SN) in the axilla area during preoperative lymphoscintigraphy. Methods: We retrospectively studied 332 women with T0, T1, or T2 3-cm, N0 invasive breast cancer who underwent a sentinel lymph node biopsy procedure. All patients had intradermal and intraparenchymal injection of 37 MBq 99mTc-sulfur colloid in a total volume of 4 0.1 mL, above and around the tumor. Anterior and lateral static views were ob-tained a few minutes and 2–4 h after injection. Surgery was per-formed the next day. The SNs were localized intraoperatively with the aid of patent blue dye and using a hand-held -probe. SNs were analyzed by serial sections stained with hematoxylin–eosin, with the adjacent section stained with anticytokeratin antibodies. Different parameters, such as the number of positive lymph nodes, presence of lymphovascular invasion, tumor size, tumor grade