Lymphoscintigraphic anatomy of sentinel lymphatic channels after subareolar injection of technetium 99m sulfur colloid

BACKGROUND: Injection of Technetium 99m sulfur colloid (Tc-99m-SC) into the subareolar lymphatic plexus provides a rapid and reliable method of identi fying breast sentinel lymph nodes and their lymphatic connections to the ar eola, termed sentinel lymphatic channels (SLCs). The objective of this stud y was to define the anatomic origin, number, and direction of the SLC in re lation to the areola after subareolar injection of Tc-99m-SC. STUDY DESIGN: Using a hand-held goniometer, the exit angle (theta (e)) and direction from the vertical (to the patient's right or left) of SLCs were d etermined in 87 successful preoperative lymphoscintigrams (46 left breast a nd 41 right breast). RESULTS: One major lymphatic trunk was identified in 91% of cases (n = 79), and two lymphatic trunks were identified in 9% of cases (n = 8). Overall, 24% (n = 21) of major lymphatic trunks exited the areola vertically (theta (e) = 0 degrees), 33% (n = 29) exited the areola with theta (e) = right or left I to 30 degrees, and 32% (n = 28) exited with a theta (e) = right or l eft 31 to 60 degrees. In total, 90% (n = 78) of SLCs exited the areola with a theta (e) = right or left 0 to 60 degrees, equivalent to 10 to 12 o'cloc k in the right breast, and 12 to 2 o'clock in the left breast. CONCLUSIONS: Radial angular measurements of SLCs from preoperative lymphosc intigrams performed by SA injection confirm that the origin of the majority of SLCs is within the upper, outer edge of the areola, and that all SLCs u ltimately traverse the upper, outer quadrant of the breast and terminate on axillary sentinel nodes. (J Am Coll Surg 2001;193:601-608. (C) 2001 by the American College of Surgeons).