Sentinel lymph node (SLN) is the first lymph node(s) in a
regional lymphatic basin to receive the lymphatic drainage
from a primary tumor. It has been shown that the lymph
flows in an orderly and predicted pattern and any metastatic
spread from a primary tumor will involve the sentinel node(s)
first, before involving other lymph nodes in that lymphatic
basin.
1 The tumor status of the SLN could then help to predict
the histopathologic status of other lymph nodes draining the
tumor.
2, 3 Although it is possible that at times, breast
metastasis may skip pass the SLN to involve the second-tier or
a higher-level node, this phenomenon is thought to be an
uncommon variant of the lymphatic pattern.
4, 5, 6 Studies have
also shown a low axillary recurrence rate in the follow-up of
patients with negative SLN. (Copied from article).