Function

Lymph nodes are the filter stations of the lymphatic system. The lymph is transported from the tissue and organs via the lymph vessel system to the lymph nodes. There, foreign bodies are detected by the immune system and can thus be fended off.

Tumors can also form metastases in the surrounding tissue via the lymphatic system. Depending on the extent of the metastasis, the prognosis of the disease can be better or worse. In addition, the extent of metastasis can influence the choice of therapy.

sentinel lymph nodes are normal lymph nodes, which are, however, located in the first place within the lymph drainage area of a tumor. They have the same function as other lymph nodes and represent filter stations. If tumor cells spread via the lymphatic path, they first accumulate in the sentinel lymph node.

The sentinel lymph node is particularly important for breast cancer and malignant skin cancer. In other types of cancer, the lymphatic flow flows in several directions, so that no statement can be made about a single sentinel lymph node. If a tumor is removed surgically, the sentinel lymph node is usually removed as well.

It plays a role in the further prognosis of the disease. Since a small sentinel lymph node can be difficult to identify, it is possible to visualize the lymph node using staining or radioactive substances. After removal of the sentinel lymph node, it is examined.

If it is free of tumor cells, the probability is low that the tumor has metastasized via the lymphatic pathway by this time. In this case, it may not be necessary to remove further lymph nodes that follow. Thus, any complaints that may arise from a radical lymph node removal can be prevented.

Nevertheless, despite the lack of tumor cells in the sentinel lymph node, metastases may still be present in subsequent lymph nodes. This is known as “metastasis leaps”. If tumor cells are found in the sentinel lymph node, there is a high probability that further metastases of the tumor are present in the surrounding lymph nodes and that these must also be removed. Accordingly, the possible detection of tumor metastases in the sentinel lymph node can be of therapeutic as well as prognostic importance. The removal of the sentinel lymph node and subsequent lymph nodes can possibly prevent the further spread of tumor cells.If the tumor has not metastasized further by this time, the complete removal of the tumor, the sentinel lymph node and the subsequent lymph nodes can create a good basis.