The lymph node is a small bean-shaped structure that is part of the body’s immune system. The lymph nodes in the body contain lymphocytes, which are white blood cells that aid in the body’s defense against disease and infection. They filter substances that pass through the lymphatic fluid. All over the body, lymph nodes number in the thousands. They are connected to one another by lymph vessels. Neck, axilla (underarm), chest, abdomen, and groin lymph node clusters are all common locations. The axilla, for instance, contains 20 to 40 lymph nodes. called the lymph gland as well.
Table of Contents
What Are Lymph Nodes?
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are important locations for lymphocytes, including B and T cells. A lymph node is a secondary lymphoid organ in the lymphatic system. An outer cortex and an inner medulla make up a lymph node, which is encased in a fibrous capsule.
Although lymph nodes don’t detoxify the body, they are crucial for the immune system’s proper operation because they serve as filters for foreign substances like cancer cells.
From minor throat infections to potentially fatal cancers, lymph nodes can swell or become inflamed as a result of a number of diseases. The condition of lymph nodes is very important in cancer staging, which decides the treatment to be used and determines the prognosis.
Structure
Lymph nodes are kidney or oval-shaped and range in size from 2 mm to 25 mm on their long axis, with an average of 15 mm.
A fibrous capsule surrounds each lymph node and extends inside it to form trabeculae surrounds each lymph node. The substance of a lymph node is divided into the outer cortex and the inner medulla. These are rich with cells. The lymph node’s concave surface has an indentation called the hilum where blood vessels enter and exit as well as lymphatic vessels leave.
Multiple afferent lymphatic vessels carry lymph into a lymph node’s convex side, where it then exits into a number of sinuses. After entering the lymph node from afferent lymphatic vessels, lymph flows into a space underneath the capsule called the subcapsular sinus, then into cortical sinuses. Lymph gathers in the medullary sinuses after passing through the cortex. These sinuses all empty into efferent lymph vessels and leave the node at the hilum on the concave side.
Size
| Generally | 10 mm |
| Inguinal | 10 – 20 mm |
| Pelvis | 10 mm for ovoid lymph nodes, 8 mm for rounded |
| Neck | |
|---|---|
| Generally (non-retropharyngeal) | 10 mm |
| Jugulodigastric lymph nodes | 11mm or 15 mm |
| Retropharyngeal | 8 mm Lateral retropharyngeal: 5 mm |
| Mediastinum | |
| Mediastinum, generally | 10 mm |
| Superior mediastinum and high paratracheal | 7mm |
| Low paratracheal and subcarinal | 11 mm |
| Upper abdominal | |
| Retrocrural space | 6 mm |
| Paracardiac | 8 mm |
| Gastrohepatic ligament | 8 mm |
| Upper paraaortic region | 9 mm |
| Portacaval space | 10 mm |
| Porta hepatis | 7 mm |
| Lower paraaortic region | 11 mm |
Clinical Significance
- Swollen
Lymphadenopathy is the term for enlargement or swelling of the lymph nodes. Infections, tumors, autoimmune disorders, drug interactions, illnesses like amyloidosis and sarcoidosis, as well as lymphoma or leukemia, are just a few of the conditions that can cause swelling. Swelling can hurt depending on the cause, especially if it happens quickly and is brought on by an infection or inflammation. Infection from a nearby source or a tumor that has spread to the lymph node may be suggested by localized lymph node enlargement. Infection, connective tissue or autoimmune disease, or a blood cell malignancy like lymphoma or leukemia could all be suggested by the fact that it is generalized. Rarely, depending on location, lymph node enlargement may cause problems such as difficulty breathing, or compression of a blood vessel (for example, superior vena cava obstruction).
- Lymphedema
Lymphedema is a condition characterized by swelling (edema) of tissue brought on by inadequate lymphatic system function. Primary lymphedema is a condition that can be congenital and is typically caused by underdeveloped or absent lymph nodes. Lymphedema typically develops in the arms or legs, but it can also affect the chest wall, genitalia, neck, and abdomen. Secondary lymphedema usually results from the removal of lymph nodes during breast cancer surgery or from other damaging treatments such as radiation. Some parasitic infections may also be the reason for it. The management of lymphedema may suggest dieting, exercise, keeping the affected limb moist, and compressing the affected area. Affected tissues are at a high risk of infection. Additionally, surgical management is occasionally taken into account.
- Cancer
Cancer can either begin there or spread there from another location, giving rise to the lymph nodes. Lymphoma is a cancer that develops in the lymph nodes. More often, cancer starts somewhere else and then spreads to lymph nodes. Lymph nodes may be imaged or even surgically removed as part of the examinations or workup for cancer. If removed, the lymph node will be stained and examined under a microscope by a pathologist to see if there is any indication of cells that seem cancerous (i.e. have metastasized into the node). Based on the presence of node metastases, cancer’s staging, and consequently the treatment plan and prognosis, are determined.
Signs to Watch For
If your lymph nodes are swollen but you don’t have any other obvious illnesses, you should visit a doctor. This is crucial if, after about two weeks, the feeling of your lymph nodes being hard to the touch still persists. Consult a doctor if any of the following symptoms are present along with swollen lymph nodes.
- Night sweats
- Fatigue
- Fever
- Abdominal pain or swelling
- Easy bruising or bleeding
- Feeling full after eating just a small amount of food
- Frequent or severe infections
- Coughing, chest pain, or shortness of breath
- Unexpected weight loss
Summary
Finally, it should be noted that lymph nodes, which can be found all over the body, are very significant for the human body. It’s important to pay attention to any changes in your body’s lymph nodes because they could be an indication of lymphedema or cancer. Learning more about your body’s lymph nodes will do you a lot of good.
