Sentinel Lymph Node: What Is It And Why Is It Important?
Oncological pathologies very often are accompanied by numerous medical procedures. The sentinel lymph node technique saves some steps and avoids unnecessary surgery.
The sentinel lymph node is the first lymph gland toward which the cells that separate from the primary tumor are directed. It is not a question of metastases in the broad sense of the term, but the mechanism is similar. From a localized tumor mass, cells move to other areas of the body and some reach the nearest lymph node.
The sentinel lymph node is of fundamental importance to identify the stage of breast cancer, therefore to determine the real extent of the neoplasm in the body. Through sentinel lymph node biopsy, the course of the disease can be predicted.
On top of that, it helps plan therapy. Based on the extent of the tumor, the appropriate treatment will be chosen between surgery, chemotherapy and radiotherapy or any other combination.
Predict the course of the disease thanks to the sentinel lymph node
Sentinel lymph node biopsy proved to be an important step forward in oncology. Before this technique, a woman with breast cancer had to undergo surgery to remove a large part of the lymphatic chain in the armpit closest to the neoplasm.
It is an invasive procedure whose most common adverse effect is lymphedema, ie the obstruction of the lymphatic circulation. Following this, the lymphatic fluid flows into the soft tissues causing the upper limb of the intervention side to swell and inflame.
The surgery to remove the entire lymphatic chain had two objectives: to diagnose the extension and to treat an already localized metastasis. Nevertheless, if the result of the next biopsy was negative, the whole operation was in vain and the patient had to face the physical consequences of the operation.
The purpose of sentinel lymph node biopsy is to avoid surgery whenever possible, thus improving the patient’s quality of life. The incision is minor and the lymph glands are removed only if the pathological anatomy reveals the presence of malignant cells.
Sentinel lymph node biopsy
Sentinel lymph node biopsy is part of the protocol for some breast cancers. The usefulness of this procedure in the presence of melanomas is being tested, but we do not yet have definitive data.
As explained, a sample of the lymph node closest to the initial tumor is taken in order to localize the presence of malignant cells. If the result is negative, it is certain that the neoplasm is localized. We proceed with a minor incision compared to that of a surgery for removal of the lymphatic chain.
This procedure, however, is not without its side effects. The most common are subsequent bleeding of the wound and infection of the incision area. Nonetheless, the risk is very low.
How to locate the sentinel lymph node?
In order to proceed with the biopsy, the sentinel lymph node must first be identified. The medical team uses some techniques that make this gland more noticeable than the others. This will allow the surgeon to pinpoint its exact location.
Radioactivity is one of the techniques used. For this purpose, a liquid solution with low radioactive power is injected near the primary tumor. A part of this solution will be absorbed by the underlying lymphatic glands making the sentinel node closest to the neoplasm radioactive and therefore visible to diagnostic instruments.
Another technique involves the use of a green or blue biological dye. Instead of using a radioactive substance, a biological dye is injected which, moving from the primary tumor, travels to the nearest lymph node making it recognizable.
The choice of the most suitable method for detecting the sentinel lymph node depends on the judgment of the medical team. They are both efficient and have minimal negative effects. The radioactive substance is injected in minimal quantities, therefore it does not cause radioactive effects on the cells.
As for the biological dye, the only drawback could be a slight blue or green color to the urine, through which it is eliminated.
How to interpret the biopsy results?
Once the biopsy has been performed, there are two ways to proceed. If the result is negative, it means that no malignant cells have been detected and therefore no other surgery will be performed. We will proceed with the staging of the neoplasm, starting the most appropriate treatment.
If the result is positive, more invasive surgery will have to be performed. It means that the cancer cells were detected in the nearby lymph nodes and then the cancer began to spread.
As we always recommend in the field of oncology, it is important to act promptly. The sooner you undergo the appropriate diagnostic tests, the sooner you can intervene with the appropriate treatment.
