What is lymphadenopathy?
The body's defense mechanisms against infectious agents are collectively called the immune system. The lymph nodes, or glands, form an important part of this system.
Lymphadenopathy simply means the enlargement of lymph nodes. Lymph glands occur in complexes (groups) in different parts of the body. These groups, as well the individual lymph nodes, are connected via very fine channels called lymphatics. Lymphatics are one cell layer in thickness and form a network throughout the body.
The fluid that runs in the lymphatics is collected from between the cells of tissues in the various parts of the body. Once the fluid has been collected from the tissues and is running in the lymph nodes, it is called lymph. Lymph nodes serve as filters for the lymph.
Once the fluid in the lymphatics has been cleared from toxins collected from around the body, it drains back into one of the major veins in the neck.
Who gets lymphadenopathy?
Everyone will experience enlargement of their lymph glands at some point in their lifetime. This is usually normal, however in certain circumstances enlarged lymph nodes may indicate a serious medical condition.
What causes lymphadenopathy?
As lymph filters through the lymph nodes, all unwanted bacterial and all other potentially harmful agents, such as cancer cells, get caught in these filters and then sets up an immune response in the lymph node. Once the harmful organism or bacteria has been caught and recognised as harmful, the lymph node swells up in order to produce specially programmed fighter cells capable of recognizing and attacking the unwanted invaders.
Swelling of the lymph glands may occur even if the infection is trivial or not apparent. The swelling generally results from localised or systemic infection, abscess formation, response to vaccinations or malignancy (cancer). Infectious agents include a whole host of viruses and bacteria. Infection is the most common cause of lymph node enlargement; other causes are extremely rare.
How is lymphadenopathy diagnosed?
Most often the diagnosis is obvious and can be made by clinical assessment alone. The clinical assessment includes a history of perhaps local infection or systemic illness and palpation (examination by feeling with the hands) and observation of the enlarged nodes.
If enlarged lymph nodes are confined to one area, for example the groin, then that area of lymphatic drainage should be examined. In the case of the groin this includes the whole of the lower limbs, the abdomen, the genitalia and the pelvis.
Whenever a cause for the enlarged glands in one complex is not obvious, it is important that the other complexes of lymph glands be examined. If multiple lymph nodes are enlarged in most complexes, i.e. generalised lymphadenopathy, this indicates the presence of a systemic illness (affects the whole body). This could be a condition such as glandular fever, or a more serious condition such as HIV, leukaemia (blood cancer), or lymphoma (lymph node cancer) itself.
To assist with finding the cause of the enlarged lymph glands, the doctor will take note of the site or area in which the lymph nodes are enlarged, the size and consistency of the enlarged node, whether the lymph nodes are fixed and the appearance of the overlying skin. These points are discussed in more detail under separate headings below.
The sites in which enlarged lymph nodes occur
Individual groups of lymph glands are situated in specific areas of the body. The area in which lymph gland enlargement occurs is of importance, as is whether it is situated in one area or whether multiple lymph gland complexes are involved. If only one lymph gland complex is involved, the lymphadenopathy is called "localised". "Generalized lymphadenopathy" refers to the situation when enlarged lymph glands are present in most lymph gland areas. When enlarged lymph nodes are felt it is very important to palpate all the possible areas where lymph nodes can be enlarged in order to establish whether the lymphadenopathy is localised or generalised. This is important when looking for the cause of enlarged lymph glands.
There are five different lymph gland complexes as outlined below, described from the head downwards.
Head and neck
The first complex is situated in the area of the head and neck, which includes the area just below the chin; the area along the underside of the jawbone; the area down the front of the neck or throat, on either side of the windpipe; the area along the back of the neck on either side of the midline; and the area behind and in front of the ears. The last group of glands is found in the hollow area above the collarbones.
Lymph glands in these areas are very often enlarged. In most cases, the enlargement is related to simple upper respiratory tract infections such as the common cold or flu, caused by a variety of different viruses and bacteria. Symptoms may include a sore throat, a runny or blocked nose, earaches and possibly ear discharges. Tonsils also form part of the lymph gland system and tonsillitis is the inflammation of the lymph gland tissue itself.
Of concern are enlarged lymph glands situated in the hollow above the collarbone, particularly on the left-hand side. This could indicate a malignant or cancerous growth in the lung, stomach or in another part of the intestines. The condition usually occurs in the older, smoking population and may be associated with symptoms such as weight loss, a chronic cough or a change in bowel habits e.g. diarrhoea, blood in the stools, constipation, abdominal pains and vomiting.
Axillary lymph gland complex
The second lymph gland complex, the axillary lymph node complex, is situated under the arm. Enlarged lymph glands in this area may be difficult to feel. The arm on the side where the lymph nodes are examined should be held in a relaxed position hanging down the side of the body while with the other hand you should feel deep into all aspects of the armpit.
Swollen glands in this area commonly occur with infections of the breast, including breast abscess, often associated with breast-feeding in women. Enlarged glands with infection are often tender. Direct inflammation or abscess formation of the lymph gland itself can occur, more often in diabetics, and causes an exquisitely tender lump, which often needs to be surgically drained.
Of concern are the enlarged lymph glands that form as a result of breast cancer. In these cases a breast lump is also present and usually occurs in women over the age of 35. An enlarged lymph gland with breast cancer indicates a cancer that is already spreading and a doctor should be consulted immediately. Remember that it is very important for women to examine their own breasts regularly.
Very hard, persistent lymph glands present in the axillary area can indicate underlying lung cancer. Once again, this usually occurs in an older individual who smokes, with associated symptoms of a chronic cough and weight loss.
Epitrochlear lymph gland complex
Another lymph gland complex situated in the arm is found just below the biceps muscle on the inside of the arm, close to the elbow. These nodes, called epitrochlear glands, may also be difficult to feel but are important to look for. Swollen glands in this area are of concern and can be indicative of local infection, HIV infection (most commonly), cancer of the lymph glands (lymphoma), or syphilis in rare cases.
Inguinal lymph gland complex
These lymph glands are situated in the groin area and usually become swollen because of local infection, although small firm mobile glands are commonly found in otherwise normal individuals. Blood and lymph all the way from the toes to the pelvis, including the sexual organs, filter through these glands and therefore they very often become swollen. Often these occur in children who walk barefoot and bump their toes, so creating a port of entry to foreign organisms and bacteria. In adults, genital infections, including sexually transmitted diseases, can be a cause of swollen, tender glands. If this is a likely cause of the lymphadenopathy, a doctor should be consulted.
Internal lymph glands
The last group of lymph glands is situated inside the body cavities, including the chest and the abdomen. These glands are not felt externally and usually do not enlarge without the enlargement of the external lymph glands also. Glands in this area include the mesenteric lymph gland complex, as indicated on the diagram.
The size of the enlarged lymph glands
The size of the enlarged glands is important. When a lymph gland is palpable, it is enlarged. As a general rule, a lymph gland is significantly enlarged when it is more than one centimeter in length.
The consistency of the enlarged lymph glands
Enlarged glands due to infection are usually soft. With lymphoma (cancer of lymph tissue), the enlarged glands feel rubbery. Rocky hard nodes usually indicate enlargement of lymph nodes due to a cancerous growth in the vicinity. For example, a rocky hard node in the axilla could indicate that a lesion seen on a chest x-ray is cancerous.
Tenderness of the lymph glands
Lymph glands that are swollen due to an infection in the area or that contain an abscess are tender when palpated.
Slow-growing and persistent lymph glands are painless and often go unnoticed, but are of concern once detected.
Is the lymph gland mobile, i.e. can it be moved from side to side? Or is the lymph gland attached to other structures, including the overlying skin and the deeper tissues underneath. Can the lymph glands be felt separately or are they matted (stuck together)? Matted lymph glands are a sure sign of tuberculosis.
When lymph glands are attached to one another or to other structures it is important to consult a doctor, as this may indicate malignancy or TB.
Appearance of the overlying skin
When the skin overlying the swollen gland is red, inflamed and tender to touch, underlying infection is present. An "orange peel" appearance, or tethering (attachment to lymph glands) of the overlying skin indicates cancerous growth.
Further diagnostic procedures
When local or regional infection is obvious and the likely cause of swollen lymph glands in a specific area, physical examination is sufficient for diagnosis. Sometimes, however, it is necessary to identify the cause of the swollen gland by examining a sample under the microscope: this is called making a tissue diagnosis.
Making a tissue diagnosis can be done in two ways:
- The first investigation is called a Fine Needle Aspiration Biopsy or FNAB. With this investigation, a thin needle attached to a syringe is inserted into a gland and through suction some of the tissue is drawn into the needle. This is then sprayed onto a glass slide, fixed with a special spray and sent to a laboratory for staining and examination under a microscope.
- If no diagnosis can be made from the few cells inspected under the microscope or the swollen lymph glands are too small or in too difficult an area for FNAB, a lymph node biopsy is needed. Here skilled surgery is needed to remove a whole lymph gland under local anaesthesia. Single cell thick slices are then cut from the removed lymph gland for examination under the microscope, using special staining methods.
Treatment and outcome of lymphadenopathy
Enlarged lymph nodes are part of the body’s natural defense mechanism against infections or the invasion of abnormal cells, such as with cancers.
Treatment is thus not directed at the enlarged lymph nodes as such but at the underlying cause of the enlargement. Often no treatment is necessary: with a healthy immune system, the invasive organisms are destroyed and lymph nodes will return to their normal size.
Further investigation, including tissue diagnosis, is required when any of the following features are present:
- persistently enlarged lymph glands
- generalised lymphadenopathy
- lymph glands appear very hard when palpated
- very large lymph glands
- attachment to other structures
Consult a doctor if you notice any of the above features.
Written by Dr Rozali Spies, MBChB, Senior Medical Officer, Victoria Hospital