Sentinel lymph node

Sentinel lymph nodes, even sentinel node, of Engl. sentinel lymph node (SLN ) is a concept in the recognition ( diagnosis) and treatment (therapy ) of certain malignant tumors ( cancer), especially breast cancer ( breast cancer), black skin cancer ( malignant melanoma) and prostate cancer ( prostate cancer).

As sentinel lymph node lymph nodes are those referred to in this concept, which lie in the first place in the drainage area of the lymph of a malignant tumor. Are lymph nodes in these associations already been abducted by tumor cells with the lymph flow, as can be found with a certain probability even further metastases in the area. By contrast, if the sentinel lymph nodes free of tumor, the probability is low that further lymph node metastases are present. Therefore, the status of the sentinel lymph node is ( infected or not infected ) in the diagnosis and further treatment of these tumors is of particular importance.

Implementation

The identification of the sentinel lymph node is done as part of a Lymphabstromszintigraphie ( sentinel lymph node scintigraphy, sentinel node scintigraphy ). For this purpose, a type of protein (nano - colloid) is labeled with radioactive 99mTechnetium and in the tumor ( intratumorally ), or in the tissue in the vicinity of the injected tumor ( peritumorally ); other possibilities are within the skin ( intradermally ), around the nipple ( periareolar ), or in the subcutaneous tissue ( subdermal ). The marker spreads through the same Lymphabflussweg as eventual tumor tissue and accumulates in one or more sentinel lymph nodes. These accumulations will be presented with the aid of a scintigraphic images and measurement probe and marked on the body surface. The number of lymph nodes to be selected varies from case to case.

The will or the sentinel lymph node can use the markers and using the measuring probe while sparing the rest of the lymph nodes ( non- sentinel lymph nodes) removed surgically targeted ( lymphadenectomy ). The discoverability of the sentinel lymph node is improved by an intraoperative combination with the dye patent blue V. The removed lymph nodes are then processed histopathologically.

Importance

The finding of the sentinel lymph node can be further statements about the metastasis of the tumor. If the sentinel node is not affected, as can be expected ( in breast cancer in 95 % of cases ) of which with high probability that subsequent lymph nodes are as little affected. In this case, therefore, the removal of all lymph nodes in the armpit is unnecessary ( axillary dissection ). So, etc. can be prevented, for example, in breast cancer side effects of lymph node removal as lymphedema. In the rare cases in which there is absolutely no sentinel lymph node, is most probably due to a tumorous involvement of lymphatic vessels or lymph nodes.