A lymphoma is a cancer of cells in the lymphatic system. The lymphatic system is a system of lymph channels and lymph glands that occurs throughout the body. Lymphomas are divided into two types - Hodgkin's lymphoma and non-Hodgkin's lymphomas. Hodgkin's lymphoma is sometimes called Hodgkin's disease.
What causes it?
The exact cause of Hodgkin's lymphoma is not known. The lymphoma develops from an abnormal cell in the lymphatic system. It is not known why the cell becomes abnormal. It is thought that something damages or alters certain genes in the cell. The abnormal cell then multiplies to make many abnormal cells, which continue to multiply to form a cancer.
Read more about the causes of Hodgkin's lymphoma.
How common is it?
Hodgkin's lymphoma affects about 2 people in every 100,000 each year. People aged 20-40 years are most often affected but there is a smaller increase in people aged 55 years and older. Slightly more men than women are diagnosed with Hodgkin's lymphoma.
About 1 in 5 people with lymphoma have a Hodgkin's lymphoma. Most lymphomas are non-Hodgkin's lymphoma.
What are the symptoms?
The most common early symptom is to develop one or more swollen lymph glands, most often on one side of the neck, in the armpit or in the groin. The swollen lymph glands tend to be painless and gradually get bigger. Various other general symptoms may also develop, including high temperature (fever), sweats, weight loss, poor appetite and feeling itchy all over your body.
If the lymphoma becomes large and presses on nearby parts of the body, various other symptoms can develop. For example, you may develop a cough or breathing problems if the tumour enlarges in the lymph glands inside your chest.
Find out more about the symptoms of Hodgkin's lymphoma.
How is it diagnosed?
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 glands.
If the biopsy confirms that you have a Hodgkin's lymphoma then further tests are usually advised. This is called staging and is very important for planning the best treatment for the lymphoma. These further tests may include a CT scan, an MRI scan, a PET scan, blood tests, a bone marrow biopsy or other tests.
Read more about the tests for Hodgkin's lymphoma.
What are the treatments?
The treatment options for Hodgkin's lymphoma include:
- Treatment for Hodgkin's lymphoma is usually with medicines that destroy the cancer cells (chemotherapy).
- Radiotherapy is also sometimes used for treatment. Radiotherapy may be used as the only treatment or together with chemotherapy.
- A stem cell transplant (sometimes called a bone marrow transplant) is not a usual treatment for Hodgkin's lymphoma because chemotherapy and radiotherapy usually cure the disease. A stem cell transplant tends to be used if the disease returns (relapses) after the initial treatment.
Find out more about the treatments for Hodgkin's lymphoma.
What is the outlook?
The outlook (prognosis) is generally very good for most people with Hodgkin's lymphoma. It often responds very well to treatment and is one of the most curable forms of cancer. About 8 or 9 people out of 10 with the disease will have permanent remission.
The cure rate tends to be highest in younger people. Virtually all young adults who are diagnosed in the early stages of the lymphoma can expect to be completely cured. It is also often possible to cure Hodgkin's lymphoma even if the initial treatments are not successful.
New treatments continue to be developed. There are some newer medicines that have been introduced in the last few years that show promise to improve the outlook.
What are the symptoms of Hodgkin's lymphoma?
The symptoms in Hodgkin's lymphoma can be very variable and affect different parts of your body.
Swollen lymph glands (nodes)
The most common early symptom is for one or more swollen lymph glands to develop in one area of the body. The most common affected area is one side of the neck but other areas often first affected are the armpit and groin. The swollen lymph glands 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 tummy (abdomen), you will not be aware of them swelling in the early stages of the disease.
The most common cause of swollen lymph glands 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 glands. 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 obvious infection to account for the swelling.
As a Hodgkin's lymphoma develops you may feel generally unwell. Various other symptoms may develop and these include:
- Fever and sweats (especially at night).
- Weight loss.
- Poor appetite.
- Looking pale and easily getting out of breath (anaemia).
- Itch all over the body.
If the lymphoma tumours become large and press on nearby parts of the body, various other symptoms can develop. For example, you may develop a cough or breathing problems if the tumour enlarges in the lymph nodes inside the chest.
What is your lymphatic system?
The lymphatic system consists of lymph nodes (often called lymph glands), a network of thin lymphatic channels (similar to thin blood vessels), and organs such as the spleen and thymus.
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 other 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 germs (bacteria, viruses, etc).
- T lymphocytes which have various functions including helping the B lymphocytes to make antibodies.
- Natural killer lymphocytes which also help to protect against infection.
What are the causes of Hodgkin's lymphoma?
The cause of Hodgkin's lymphoma is not known but it may be more likely in some situations:
- 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, yet only a few will 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.
Hodgkin's lymphoma is not an inherited (genetic) condition and does not run in families. However, an identical twin of a person with Hodgkin's lymphoma has a slightly higher risk of developing Hodgkin's lymphoma.
The cancerous lymphocytes tend to collect in lymph glands (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.
How is Hodgkin's lymphoma diagnosed?
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 glands (nodes). During a biopsy procedure 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. Usually an entire lymph gland 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 is only found in Hodgkin's lymphoma. Only about 1 in 1,000 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 subtypes 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 are similar for all the types of Hodgkin's lymphoma.
How do you assess the extent and spread of the lymphoma?
If the biopsy confirms that you have a Hodgkin's lymphoma then further tests are usually advised. For example, you may have a computerised tomography (CT) scan, a magnetic resonance imaging (MRI) scan, a positron emission tomography (PET) scan, blood tests, a bone marrow biopsy or other tests. (See separate leaflets which 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 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 lymphoma is:
- Stage I - the lymphoma affects one group of lymph nodes only.
- Stage II - 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 tummy (abdomen) and helps us to breathe. So, for stage II, all the affected nodes will either be above or below the diaphragm.)
- Stage III - the lymphoma affects nodes on both sides of the diaphragm.
- Stage IV - 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, high temperature (fever) or weight loss. B means that you do have one or more of these symptoms.
As an example, if you have Stage IIB, it means that you have two or more groups of lymph nodes affected; however, 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. See separate leaflet called Staging and Grading Cancer for more detail.
What are the treatments for Hodgkin's lymphoma?
Treatment for Hodgkin's lymphoma is usually with medicines that destroy the cancer cells (chemotherapy), with or without radiotherapy.
Chemotherapy is a treatment which uses anti-cancer medicines to kill cancer (lymphoma) cells, or to stop them from multiplying. Hodgkin's lymphomas are usually treated with chemotherapy medicines given straight into the vein (intravenous chemotherapy). The course of chemotherapy typically lasts several months. A combination of medicines is usually used. The exact combination of medicines used and the length of the course of chemotherapy depend on factors such as the stage and exact type of the disease.
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.
What about a 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 tends to be used if 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.
You should have a full discussion with a specialist who knows your case. They will be able to give you information on:
- The pros and cons.
- The likely success rate.
- Possible side-effects.
- Other details about the treatment options for your type and stage of Hodgkin's lymphoma.
Further reading & references
- Hodgkin's lymphoma: ESMO Clinical Practice Guidelines for diagnosis treatment and follow-up; European Society for Medical Oncology (2014)
- Guideline on the Management of Primary Resistant and Relapsed Classical Hodgkin Lymphoma; British Committee for Standards in Haematology and the British Society of Blood and Marrow Transplantation (2013)
- Classical Hodgkin Lymphoma - First Line Management; British Committee for Standards in Haematology (2014)
- Ansell SM; Hodgkin lymphoma: 2016 update on diagnosis, risk-stratification, and management. Am J Hematol. 2016 Jun;91(4):434-42. doi: 10.1002/ajh.24272.
- Gobbi PG, Ferreri AJ, Ponzoni M, et al; Hodgkin lymphoma. Crit Rev Oncol Hematol. 2013 Feb;85(2):216-37. doi: 10.1016/j.critrevonc.2012.07.002. Epub 2012 Aug 4.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Colin Tidy
Dr John Cox