Cancer patients often come across the term 'lymph nodes' and might be a bit confused about its use. While determining the stage of a cancer, the doctor first checks whether the cancer has spread to the nearby lymph nodes or not. What does the statement "the cancer has not yet invaded the nearby lymph nodes" mean? What are these lymph nodes? How do they help determine the mode of treatment? To help you find answers to these questions, here is an overview of lymph node locations and their significance in cancer treatment.
The lymphatic system consists of organs like spleen, adenoids, tonsils, thymus, etc. The main function of this system is to transport a watery clear fluid 'lymph' which carries immune cells called 'lymphocytes' and mainly the 'chyle' from intestines, which contains essential factors like proteins and fats. Thus, the lymphatic system promotes circulation of the essential elements throughout the body. Lymphatic system is a part of the body's immune system, as it protects the body organs from disease-causing antigens like viruses, bacteria, etc. It thus helps strengthen the immune system. It also helps maintain perfect fluid balance in the body. Very high lymphocyte count can cause lymphoma, a condition wherein lymph nodes enlarge and get transformed into malignant tumors. Lymphatic ducts run parallel to blood vessels; but unlike the circulatory system, the lymphatic system is a one-way street, draining lymph from the tissue and returning it to the blood.
The lymph fluid can pass easily from tissues into lymph ducts as they are very permeable. Lymph nodes act as filters of lymph, just as spleen acts as a filter of blood. Lymph nodes are present at various locations in the body and are connected by lymphatic vessels. The nodes are usually found in clusters. They are also known as lymph glands. These small, bean-shaped glands act as traps for foreign particles. They help remove harmful bacteria and cancer cells. In case of painful lymph nodes (or swollen nodes) under arm, you should consult your physician immediately. Inflamed or enlarged nodes can be observed in various conditions like throat infection, tonsillitis, etc. Normal lymph nodes range in size from a few millimeters to about 1 - 2 cm. It is an interesting fact that the size of the nodes in adults is smaller than the size of the nodes in children belonging to the age group 10 - 12.
Lymph Nodes and Cancer
Lymph nodes play a very important role in staging of a cancer which helps determine the course of the treatment. In the initial stage of a cancer, the malignant tumor is confined to its origin. As the cancer enters the next stage, the tumor grows, multiplies, and invades the nearby lymph nodes. During the advanced stage, blood and lymph carry the cancerous cells throughout the body and the cells attack distinct organs. If the cancer is diagnosed when it is at an earlier stage, surgical removal of the cancer is possible. If required, the doctor may remove the lymph nodes too. To kill the remaining cancerous cells, treatments like chemotherapy and radiation therapy are usually recommended.
Clusters of lymph nodes are present in underarms, groin, neck, chest, and abdomen. There are about 500 - 600 nodes distributed throughout the human body. Here is a list of major groups of lymph nodes. They are classified according to their location. The following table will explain it clearly:
|Location||Type of Lymph Nodes||Sub-Division||Description|
|Head and Neck||Cervical Lymph Nodes||Anterior Cervical||Above and beneath the sternocleidomastoid muscles (anterior portion of the neck)|
|--||--||Posterior Cervical||Posterior to the sternocleidomastoids but in front of the trapezius muscle|
|--||Tonsillar (sub mandibular)||--||Below the angle of the mandible|
|--||Sub-mandibular||--||Along the underside of the jaw on either side|
|--||Sub-mental||--||Just below the chin|
|--||Supraclavicular lymph nodes||--||In the hollow above the collarbone, just lateral to where it joins the breast bone.|
|Thorax||Nodes of the Lungs||Subsegmental, Segmental, Lobar, Interlobar, Hilar||Around the lungs|
|--||--||Mediastinal||Along the trachea and the esophagus and between the lung and the diaphragm.|
|--||Abdominal Lymph Nodes||--||Along the esophagus and the stomach|
|Arm||Superficial Lymph Glands||Supratrochlear Glands||Above the medial epicondyle of the humerus, medial to the basilic vein|
|--||--||Deltopectoral Glands||Between the pectoralis major and deltoid muscles inferior to the clavicle.|
|--||Deep Lymph Glands (Axillary/Arm Pit)||Lateral Glands||--|
|--||--||Anterior or Pectoral Glands||--|
|--||--||Posterior or subscapular Glands||--|
|--||--||Central or intermediate Glands||--|
|--||--||Medial or subclavicular Glands||--|
|Lower Limbs||Superficial Inguinal Lymph Nodes||--||Below the inguinal ligament, deep to Camper's fascia|
|--||Deep Inguinal Lymph Nodes||--||Medial to the femoral vein and under the cribriform fascia|
|--||Popliteal Lymph Nodes||--||In the fat contained in the popliteal fossa.|
Doctors usually check for swollen lymph nodes at the time of physical examination. Healthy nodes are not sensitive to touch and they maintain their normal size. Thus, these nodes help analyze the physical condition of an individual.