To determine how often the sentinel lymph node (SLN) draining the breast is the same node as the SLN draining the upper limb. A common SLN might increase the risk of upper limb breast cancer-related lymphoedema after SLN biopsy.Methods
Patients with invasive breast cancer, identified as being suitable for axillary lymph node dissection, were injected preoperatively with 40 MBq of technetium-99m (99mTc)-human polyclonal immunoglobulin G intradermally into the ipsilateral breast and 3 MBq of indium-111 (111In)-human polyclonal immunoglobulin G intradermally into the ipsilateral hand, or vice versa. Axillary lymph nodes were removed, separated and assayed in a well counter for 99mTc and 111In.Results
Fifteen patients entered the study. In 13 of 15 patients, the ‘hottest’ lymph node for 99mTc was separate from the ‘hottest’ lymph node for 111In. In two of 15 patients the ‘hottest’ lymph node for 99mTc was also the ‘hottest’ lymph node for 111In, suggesting a common drainage pathway from the ipsilateral breast and upper limb.Conclusion
Although the majority of patients has different pathways of lymphatic drainage from the ipsilateral breast and upper limb, in a small minority of patients the drainage pathway is through a common SLN. Such patients may be at increased risk of developing upper limb breast cancer-related lymphoedema after SLN biopsy.