Adenopathy known also as Lymphadenopathy or adenomegaly is an enlargement of the lymph nodes, which can be due to bacterial, viral infections, or cancer.
Lymph Nodes. Image Courtesy of Bruce Blaus.
When the lymph nodes in the mediastinum are involved, it is called mediastinal lymphadenopathy, cervical lymphadenopathy when the enlarged lymph nodes in the neck are involved, or axillary lymphadenopathy when the lymph nodes in the armpits are enlarged. It can also be inguinal if it is affecting the inguinal nodes. Adenomegaly is usually the result of a great strain on the immune system, of which the lymph nodes are an important part.
Adenomegaly (Lymphadenopathy or adenopathy), what is it?
Etymologically, adenomegaly means an increase in the size of the glands: the term comes from Greek, “aden” means gland and “mega” means large. Thus, adenomegaly (Lymphadenopathy or adenopathy) is an enlargement of the lymph nodes, as a result of an infection by a virus, a bacterium, or a parasite, or a tumor.
Lymph nodes are nodes along the lymph vessels in certain parts of the body:
The mediastinal lymph nodes are located in the mediastinum, the middle area of the rib cage (located between the two lungs, near the heart, trachea, bronchi, and esophagus). When they are enlarged, it is called mediastinal lymphadenopathy.
The cervical lymph nodes are located in the neck: when they are enlarged, cervical lymphadenopathy is present.
If the adenomegaly affects the lymph nodes under the armpits, it is called axillary adenopathy.
Finally, when this hypertrophy affects the lymph nodes in the groin area, i.e. the lymph nodes in the groin, it is called inguinal lymphadenopathy.
How do you recognize adenomegaly (Lymphadenopathy or adenopathy)?
Hypertrophy of the lymph node is usually detected by the doctor during a clinical examination. It is indeed by palpation that the doctor can detect abnormal lumps at the level of these lymph nodes.
The patient may sometimes feel the appearance of a small “lump” or “mass” in the armpits, neck, or groin, sometimes accompanied by fever.
Other methods can confirm the diagnosis, such as ultrasound and other types of imaging tests. Especially in the chest, these mediastinal lymphadenopathies are localized by means of a CT scan of the chest and, depending on the location, the diagnosis can also be made by means of a mediastinoscopy (examination of the mediastinum by means of an endoscope), a mediastinotomy (incision of the mediastinum), or a thoracoscopy. Histology, by studying the cells, makes it possible to determine whether the adenopathy is malignant or not.
Risk factors
Immunocompromized people run a higher risk of infection and thus of developing adenomegaly: patients with HIV, for example, or patients undergoing immunosuppressive therapy.
The infection itself is a risk factor for adenomegaly.
Causes
Lymph nodes are nodes used to filter lymph. They also play an essential role in the body’s immune response, and thus in its defense.
It is in these nodes that foreign antigens (which are infectious microorganisms that can be bacteria, viruses, or parasites) are presented to cells of the immune system called T cells and B cells (white blood cells).
After this antigen presentation, the body’s immune response will be activated against the infectious agents or the body’s own abnormal (often tumor-like) cells. This response involves the production of antibodies by B cells (also called humoral immunity), or cellular response, also called a cytotoxic response, involving CD8 T cells (also called cellular immunity).
It is this activation of the immune response within the lymph node that explains the hypertrophy in adenomegaly: the multiplication of the number of lymphocytes quickly leads to an increase in the size of the lymph node. In addition, cancer cells can also infiltrate the lymph node, which in turn increases its size. Inflammatory cells can also multiply in the lymph node, and even the lymph node’s own immune cells can multiply, resulting in lymph node cancer.
Benign causes
The most likely benign causes of enlarged lymph nodes are:
- Sarcoidosis (widespread disease of the body with unknown cause)
- Tuberculosis, which is especially detected by mediastinal lymphadenopathy
- and other curable infectious diseases, such as mononucleosis caused by Epstein-Barr virus, etc
Malignant Causes
The most likely malignant causes of enlarged lymph nodes are:
- Tumors, cancers, and metastases, such as Hodgkin’s or non-Hodgkin’s lymphomas, which are also very often diagnosed by mediastinal adenopathy (after chest X-ray);
- Autoimmune diseases: especially lupus, or rheumatoid arthritis
- More serious infections, e.g., related to the AIDS virus, HIV, or viral hepatitis, etc.
Risks of complications
The main risks of complications of adenomegaly are indeed related to its etiologies:
- In the case of tumors, the pathology may develop into malignant tumors or even the appearance of metastases, i.e. the spread of cancer cells at a distance from the adenopathy.
- Infection with HIV, the AIDS virus, is an acquired immune deficiency, i.e. an increased risk of contracting all types of infections.
- Autoimmune diseases also develop with the risk of severe complications that can lead to severe pain and disability.
Treatment and prevention of adenomegaly (Lymphadenopathy or adenopathy)
- Treatment depends on the disease diagnosed in relation to the enlarged lymph node:
- Antibiotic or antiviral treatment, or even antiparasitic treatment if the presence of an enlarged lymph node is due to a pathogen (bacteria, virus, or parasite)
- Cancer treatment in the case of a tumor, which may combine radiation and chemotherapy;
- Immunosuppressants, for example, in the case of autoimmune diseases.
- In some cases, the lymph node is removed by surgery.
Adenomegaly is, therefore, a symptom that is essential to recognize as early as possible and to inform the attending physician quickly: The physician may perform a clinical examination by palpation if a conspicuous mass is felt in the neck, axilla, or groin region, or detect it on a chest X-ray in the case of mediastinal adenopathies. This medical professional can decide what treatment to start or which specialist to consult. Therefore, the earlier the cause of adenomegaly is treated, the greater the chances of recovery.
References
https://www.ncbi.nlm.nih.gov/books/NBK558918/
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