Description and alternative names
"Swollen glands" is a term used to describe the enlargement of one or more lymph nodes.
There are approximately 500 - 600 lymph nodes in the body, some of which are arranged in clusters in the abdomen, chest, neck, groin and under-arm (axilla). These nodes are not strictly glands, as they do not secrete, but rather act as filters for foreign material, bacteria, viruses and cancer cells. The average node is kidney-shaped, soft and varies in size from a few millimeters to 1-2cms.
A network system of lymph channels - similar to thin-walled tiny veins - is found everywhere in the body. Their function is to collect tissue fluids for filtration by the nodes. These channels feed into the nodes, which are connected with each other, and eventually all link up into two major lymphatics, which return the filtered fluid to the heart to re-enter the circulation. In this way, no fluids are lost.
The lymph nodes are not just passive filters. They contain special white cells called lymphocytes, which are activated when bacteria, viruses or cancer cells are detected and need to be destroyed.
When a node becomes active, it enlarges, mainly due to the increase in the number of these lymphocytes, and the swelling may remain for a time after the activity has died down. If the lymphatic system fails to drain efficiently, the tissues it should be draining may become swollen, causing a condition called Lymphoedema. The nodes or lymph channels may themselves become infected, and these conditions are called Lymphadenitis and Lymphangitis respectively.
Tonsils, adenoids and the spleen are also active lymphatic tissues forming part of the lymphatic system.
In assessing swollen glands for diagnosis of the cause, it is helpful to categorise the problem as affecting either
- a single node or group of nodes, for example only those under the chin, or those under the armpit or
- several groups of nodes - this is called a generalised lymphadenopathy.
The approach will give clues as to the most likely underlying causes. As a rough guide, local node enlargement usually indicates a local problem, affecting a particular region of the body, namely the area drained by the specific group of enlarged nodes. Generalised node enlargement usually indicates a systemic disorder, such as one affecting the whole body. Findings on examination - listed below - will further help to reach a diagnosis of the specific problem.
Common causes of enlarged nodes
Infection is the most common cause of swollen nodes, and this includes
- bacterial infections such as streptococcal pharyngitis, skin infections, cat scratch disease, typhoid, diphtheria and sexually transmitted diseases.
- viral infections - infectious mononucleosis, mumps, HIV, herpes virus, hepatitis B
- mycobacteria - tuberculosis
- fungus/protozoan/spirochaetal infections
Cancer is also a very common cause of enlarged lymph nodes. The involvement may be
- primary, for example lymphoma or Hodgkin's disease, implying a cancer of the lymphatic system itself. This may appear as a generalised gland enlargement. Leukaemia which arises in the bone marrow may also first appear as a generalised lymphadenopathy.
- secondary, in which the enlargement is due to the node-trapping cancerous cells being drained from another part of the body, and which then multiply within the node. This form is usually seen as enlargement of nodes in a single region of the body, and indicates spread of the disease beyond the site of the original cancer, for example spread of a malignant melanoma on an arm or leg.
Immunological causes include
- serum sickness, a particular type of allergic response
- drug reactions - some drugs know to cause node enlargement are
Other miscellaneous causes include
- systemic lupus erythematosus
- rheumatoid arthritis
- lipid storage diseases
- Castelman's disease and Kawasaki disease
Diagnosis - clinical and special tests
Questions asked of the patient, and the examination by the doctor, should be aimed at obtaining information about the aspects below.
The historyshould include details about injuries, fever, night sweats, weight loss, medication used, foreign travel, and high risk behaviour (including use of injected drugs, and sexual behaviour).
Examination should look for signs of systemic disease, such as an enlarged spleen. Regional groups of nodes, especially, should be carefully examined for
- location - regional nodes drain known areas, indicating where the problem may lie. If several regions are involved, it is more likely to be a systemic disorder/disease
- size - most nodes larger than 1cm in diameter are abnormal
- consistency - fibrosis causing hard nodes may be due to previous inflammation, or to some cancers which induce fibrous change in the nodes. The generalised node enlargement of leukaemia is usually soft, whilst lymphoma and chronic leukaemia are associated with firm, rubbery nodes
- fixation - unlike the normal mobile node, abnormal nodes tend to become fixed to each other, or to the tissues around them. This may be due to inflammation, or to invasion by cancer cells
- tenderness - any sudden enlargement of a node causes stretching, which may be painful. The enlargement may be due to inflammation, bleeding, cancer or merely due to increased activity of the node.
Some enlarged nodes are internal - for example in the abdomen or around the airways inside the chest. These are not visible, but may produce symptoms such as coughing, bleeding, recurrent chest infections, abdominal pain or intestinal obstruction. Careful examination - for example of the abdomen in a thin patient - may reveal these nodes, but often they are only found with special investigations.
Diagnostic tests chosen are based on physical findings.
Those with generalised lymphadenopathy should have
- a full blood count and peripheral smear - this gives the total cell count as well as a report on any abnormal (malignant or infective) forms of cells present
- chest X-ray - this will reveal internal gland enlargement (hilar adenopathy) and may also show underlying lung disease such as tuberculosis, or even secondary cancer deposits.
- HIV testing may be appropriate
- Any suggestion of malignancy must be followed up with a biopsy of an enlarged node, to give an unequivocal tissue diagnosis.
- Other imaging studies, such as scans, are not generally helpful in diagnosis, but may help in certain selected cases.
Those with localised node enlargement often have the cause found on physical examination. If no signs of malignancy are found, some doctors may merely observe for a week or two. If no change has occurred, it then becomes essential to make a diagnosis by means of a biopsy. This involves obtaining a sample of tissue for special microscopic examination. Taking a sample with a fine needle is not recommended, because the sample is too small and may miss a crucial part of the node. Open biopsy remains the gold standard for diagnosis. Under local or general anaesthesia, one or more entire nodes can be removed for analysis. Because the architecture of the whole node is preserved, a very accurate diagnosis can be made this way.
For painful, infected nodes, it may be necessary to incise them to drain the pus and relieve the pain. This pus can be analysed, giving clues to the organism causing the infection.
Treatment and outcome
The treatment and outcome will vary according to the cause of the enlargement.
As the vast majority of swollen glands are due to infections, the outcome for these is generally good. Bacterial infections are treated with antibiotics, whilst there is no effective treatment for common viral infections. For these, symptomatic relief is given with pain-killers.
Specific treatment for some conditions such as tuberculosis, fungus infections, is also usually successful, though the gland enlargement may persist for a long time after the disease is brought under control.
Cancers are referred to oncologists for management. Some types require surgery, which may include removal of the primary cancer site as well as the group of affected lymph nodes. This is often done not as a curative procedure, but to lessen the tumour bulk, making chemotherapy or radiotherapy more likely to succeed.
Regular follow-up examinations of lymph nodes may detect cancer recurrence, and allow prompt treatment.
Enlarged glands are not always a problem - often, the enlargement is temporary, and merely a sign of the immune system working efficiently. However, any gland enlargement must not be ignored, because specific treatment may be necessary.
Immunisation, where available, against common viral illnesses may prevent some episodes of viral gland enlargement.
Good hygiene, especially of the skin, and avoiding high-risk behaviour will also decrease the incidence of bacterial infections.
Sensible eating patterns and lifestyle habits will contribute towards overall good health and an effective immune system.
Cancer may not be avoidable, but not smoking and limiting exposure to sunlight are sensible steps to take.