Small lymph nodes occur throughout the body. Lymph nodes that are near each other often form into groups or chains. For example, in the sides of the neck (cervical lymph nodes), the armpits (axillary lymph nodes), and in the groins (inguinal lymph nodes). The diagrams above show the main groups of lymph nodes (lymph glands), but lymph nodes occur in many places in the body.
Lymph nodes are joined together by a network of lymphatic channels. Lymph mainly consists of a fluid that forms between the cells of the body. This contains nutrients and waste products which go into and out of cells. The watery lymph fluid travels in the lymph channels, through various lymph nodes, and eventually drains into the bloodstream.
The lymphatic system is also a major part of the immune system. Lymph and lymph nodes contain white blood cells called lymphocytes and antibodies which defend the body against infection. The lymphocytes are made in the bone marrow. When they are mature they are released into the bloodstream and migrate into the lymphatic system.
There are three types of mature lymphocytes:
- B-lymphocytes which make antibodies that attack infecting bacteria, viruses, etc.
- T-lymphocytes (which finish off their maturing in the thymus gland) have various functions including helping the B-lymphocytes to make antibodies.
- Natural killer lymphocytes also help to protect against infection.
What is cancer?
Cancer is a disease of the cells in the body. The body is made up of millions of tiny cells. There are many different types of cell in the body, and there are many different types of cancer which arise from different types of cell. What all types of cancer have in common is that the cancer cells are abnormal and do not respond to normal control mechanisms. Large numbers of cancer cells build up either because they multiply 'out of control', or they live much longer than normal cells would do, or both. Lymphoma is one type of cancer.
A malignant tumour is a 'lump' or 'growth' of tissue made up from cancer cells which continue to multiply. Malignant tumours invade into nearby tissues and organs which can cause damage.
Malignant tumours may also spread to other parts of the body. This happens if some cells break off from the first (primary) tumour and are carried in the bloodstream or lymph channels to other parts of the body. These small groups of cells may then multiply to form 'secondary' tumours (metastases) in one or more parts of the body. These secondary tumours may then grow, invade and damage nearby tissues, and spread again.
Some cancers are more serious than others, some are more easily treated than others (particularly if diagnosed at an early stage), some have a better outlook (prognosis) than others.
So, cancer is not just one condition. In each case it is important to know exactly what type of cancer has developed, how large it has become, and whether it has spread. This will enable you to get reliable information on treatment options and outlook. See separate page called 'What are Cancer and Tumours' for further details about cancer in general.
What causes Hodgkin's lymphoma and how does it develop?
The cause of Hodgkin's Lymphoma is not known. If you have a poorly functioning immune system (for example, if you have AIDS) your risk of developing a Hodgkin's lymphoma is increased. However, this only accounts for a small number of cases. A previous infection with a virus called the Epstein Barr virus (which causes glandular fever) may increase the risk slightly. However, many people have an infection with the Epstein Barr virus, and the vast majority do not develop Hodgkin's lymphoma.
What seems to happen is that a cancer (such as a lymphoma) starts from one abnormal cell. In the case of Hodgkin's lymphoma, the cancer develops from a B-lymphocyte cell which becomes abnormal. The exact reason why the cell becomes cancerous is unclear. It is thought that something damages or alters certain genes in the cell. This makes the cell abnormal. If the abnormal cell survives it may multiply and produce many abnormal cells.
The cancerous lymphocytes tend to collect in lymph nodes. The lymph nodes then get bigger and form cancerous tumours. Some abnormal cells may travel to other parts of the lymphatic system. You may therefore develop lots of large cancerous lymph nodes, and an enlarged spleen.
Who gets Hodgkin's lymphoma and how common is it?
Anyone can be affected by Hodgkin's Lymphoma, including children. However, most cases occur between the ages of 15 and 35 years, or after the age of 50. (It is one of the few cancers where there is a peak of incidence in young adults.) Men are more commonly affected than women.
What are the symptoms of Hodgkin's lymphoma?
Swollen lymph nodes
The most common early symptom of Hodgkin's Lymphoma is to develop one or more swollen lymph nodes in one area of the body - most commonly the side of the neck, the armpit or the groin. The swollen lymph nodes tend to be painless and gradually get bigger. (A symptom which occurs in about 1 in 10 cases is pain in the affected lymph glands after drinking alcohol.) If the affected lymph nodes are in the chest or abdomen, you will not be aware of them swelling in the early stages of the disease.
(Note: the most common cause of swollen lymph nodes is infection. For example, it is very common to develop swollen nodes in the neck during a bout of tonsillitis. Lymphoma is an uncommon cause of swollen lymph nodes. However, a lymphoma may be suspected if lymph nodes remain swollen for more than a couple of weeks or so, or if there is no infection to account for the swelling.)
Other symptoms
Various other general symptoms may develop in a case of Hodgkin's Lymphoma. For example: sweats (especially at night), fevers, weight loss, tiredness, being off food, anaemia, itch all over the body.
As a Hodgkin's lymphoma develops you may feel generally unwell. If the lymphoma tumours become large and press on nearby parts of the body, various other symptoms can develop. For example, you may develop cough or breathing problems if the tumour enlarges in the lymph nodes inside the chest.
How is Hodgkin's lymphoma diagnosed and assessed?
To confirm the diagnosis (biopsy)
If your doctor suspects that you may have a Hodgkin's lymphoma you will be referred to a specialist. A specialist will normally arrange a biopsy of one of the swollen nodes. A biopsy is when a small sample of tissue is removed from a part of the body. The sample is then looked at under the microscope to look for abnormal cells . (Sometimes an entire lymph node is removed to look at under the microscope.)
In Hodgkin's lymphoma, a cell called the Reed-Sternberg cell is seen when the biopsy sample is examined under the microscope. (This cell is named after the two doctors who first described it. The Reed-Sternberg cell is a B-lymphocyte that has become cancerous.) The presence of the Reed-Sternberg cell confirms the diagnosis as it it only found in Hodgkin's lymphoma. Only about 1 in 1000 of the cells in a Hodgkin's lymphoma are Reed-Sternberg cells. There are various other cells which make up the tumour. However, Reed-Sternberg cells are the characteristic cancerous cells found in this condition.
There are various sub-types of Hodgkin's lymphoma. The cells in the biopsy sample can be tested in various other ways to find out exactly which type it is. However, all types include the characteristic Reed-Sternberg cell, and the treatment and outlook is similar for all the types of Hodgkin's lymphoma.
Assessing the extent and spread (staging)
If the biopsy confirms that you have a Hodgkin's lymphoma, then further tests are usually advised. For example, you may have a CT scan, an MRI scan, blood tests, a bone marrow biopsy, or other tests. (There are separate pageswhich describe each of these tests in more detail.) This assessment is called 'staging'. The aim of staging is to find out how much the lymphoma has grown locally, and whether it has spread to other lymph nodes or to other parts of the body. The staging system that is commonly used for Hodgkin's lymphomas is:
- Stage 1 - The lymphoma is confined to one group of lymph nodes only.
- Stage 2 - The lymphoma affects two or more groups of lymph nodes. However, they are all on the same side of the diaphragm. (The diaphragm is the large muscle that separates the chest from the abdomen and helps us to breathe. So, for stage 2, all the affected nodes will either be above or below the diaphragm.)
- Stage 3 - The lymphoma affects nodes on both sides of the diaphragm.
- Stage 4 - The lymphoma affects parts of the body outside of the lymphatic system.
Each stage is also divided into A or B. A means that you do not have symptoms of night sweats, fevers or weight loss. B means that you do have one or more of these symptoms. So, for example, if you have Stage 2B, it means that you have two or more groups of lymph nodes affected, but both are either above or below the diaphragm, and you also have one or more of night sweats, fevers or weight loss.
By finding out the stage of the lymphoma it helps doctors to advise on the best treatment options.
What are the treatments for Hodgkin's lymphoma?
Treatment for Hodgkin's lymphoma is usually chemotherapy and/or radiotherapy
Chemotherapy
Chemotherapy is a treatment which uses anti-cancer drugs to kill cancer (lymphoma) cells, or to stop them from multiplying. Hodgkin's lymphomas are usually treated with chemotherapy drugs given straight into the vein (intravenous chemotherapy). The course of chemotherapy typically lasts 4-6 months. A combination of drugs is usually used. The exact combination of dugs used, and the length of the course of chemotherapy depends on factors such as the stage and exact type of the disease. (There is a separate page which gives more details about chemotherapy.)
Radiotherapy
Radiotherapy is a treatment which uses high energy beams of radiation which are focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying. Radiotherapy alone may be used for early-stage disease. It may also be used in combination with chemotherapy. (There is a separate page which gives more details about radiotherapy.)
Stem cell transplant
A stem cell transplant (sometimes called a bone marrow transplant) is not a usual treatment as chemotherapy and radiotherapy usually cure the disease. It is used is some cases, particularly in those where the disease returns (relapses) after the usual treatment. Stem cells are the immature cells that develop into mature blood cells in the bone marrow. Lymphocytes are derived from blood stem cells. Briefly, a stem cell transplant involves high dose chemotherapy (and sometimes radiotherapy) to kill all the abnormal lymphocytes. However, this also kills the stem cells that make normal blood cells. So, after the chemotherapy you are given a transplant of stem cells which then make normal blood cells. (See page called 'Stem Cell Transplant' for details.)
You should have a full discussion with a specialist who knows your case. They will be able to give the pros and cons, likely success rate, possible side-effects, and other details about the treatment options for your type and stage of Hodgkin's lymphoma.
What is the prognosis (outlook)?
The prognosis is generally very good. Hodgkin's disease often responds very well to treatment and is one of the most curable forms of cancer. Overall, if you include all people with stages 1-3, more than 8 in 10 can expect to be cured. The cure rate tends to be highest in younger people. So, for example, virtually all young adults with early stage disease can expect to be completely cured. Even for stage 4 disease, more than 6 in 10 people can expect to be cured.
Further help and information
Lymphoma Association
PO Box 386, Aylesbury, Buckinghamshire, HP20 2GA
Helpline: 0808 808 5555 Web: www.lymphoma.org.uk
CancerBACUP
3 Bath Place, Rivington Street, London, EC2A 3JR
Tel: 0808 800 1234 Web: www.cancerbacup.org.uk
Provides information and support to anyone affected by cancer.
Other support groups
See Self Help UK for a list of self help and support groups for cancer patients.
