Sentinel Lymph Node Biopsy in Breast Cancer Surgery

Excerpt

Bartholin first noticed the existence of the lymphatics in 1653 and, in the 1700s, Sappey first mapped breast lymphatics. In the 19th century, Virchow put forward the view that lymph nodes filtered lymph1 and, in 1940, Gilchrist showed that when injected, carbon traveled and was retained in the regional lymph nodes.2 In 1954, Zeidman and Buss reported that injected cancer cells arrested in lymph nodes and these cells remained in the first regional draining node for 3 weeks. In 1967, Fisher and Fisher reported that 40 % of radiolabeled cancer cells were retained in the node or nodes that drain a cancer.3,4 These observations provided the basis for the sentinel lymph node concept. The validity of sentinel node biopsy is based on two principles: first, the existence of an orderly and predictable pattern of lymphatic drainage to a regional node basin and, second, that the first node or nodes act as an effective filter for tumor cells. Sentinel lymph node biopsy was first introduced as part of breast cancer nodal staging by Giuliano et al. in 1994 using blue dye alone.5 Simultaneously, the use of isotopes was developed by Krag et al., and together these studies established the role of blue dye and radioisotope in sentinel lymph node biopsy in breast cancer.6 Anatomically, one or two large lymph trunks leave the areola and these drain mainly to the lower axillary nodes.7 Where there are two lymphatic trunks, these either combine and drain to one node or, more commonly, drain to two different sentinel nodes. Sentinel lymph nodes usually have a clearly defined anatomical location in the lower axilla. The presence of two lymphatic trunks in many explains why there is rarely one sentinel lymph node, and why false negatives can occur if the node draining one trunk but not the node or nodes draining the second trunk are removed. …