What are T-cell lymphomas?
Lymphoma happens when a lymphocyte (a type of white blood cell) goes out of control. Lymphocytes normally fight infection as part of your immune system. They are carried around your body in your lymphatic system.
There are 2 types of lymphocytes: T lymphocytes (T cells) and B lymphocytes (B cells). Both types of lymphocyte are important in protecting your body from infection and illness, but they each do this in a slightly different way.
Lymphomas can be grouped as Hodgkin lymphomas or non-Hodgkin lymphomas, depending on the types of cell they contain. Hodgkin lymphomas develop from abnormal B cells. Non-Hodgkin lymphomas can develop from abnormal T cells or B cells. All T-cell lymphomas are a type of non-Hodgkin lymphoma.
T cells are made in the bone marrow (the spongy tissue in the centre of your bones where blood cells are made) as immature (unspecialised) T cells. They then mature into specific types of T cell in the thymus gland, before moving to the lymph nodes (glands), where they stay.
T-cell lymphomas can develop from immature T cells or mature T cells.
Who gets T-cell lymphomas?
T-cell lymphomas are rare. They make up about 1 in 10 cases of lymphoma.
Most T-cell lymphomas develop from mature T cells. These types of lymphoma usually affect adults. They are more common in men than in women. On average, these lymphomas develop in people around the age of 60.
In most cases, it is not known what causes T-cell lymphoma.
In a few types of T-cell lymphoma, research has shown that certain viral infections or medical conditions can increase the risk of developing lymphoma. However, it is important to remember that only a small proportion of people with these conditions go on to develop lymphoma.
- The human T-lymphotropic virus 1 (HTLV1) is linked with development of adult T-cell leukaemia/lymphoma (ATLL).
- Past infection with Epstein-Barr virus (EBV) is linked to the development of many types of lymphoma, including angioimmunoblastic T-cell lymphoma (AITL).
- Enteropathy-associated T-cell lymphoma (EATL) is linked with coeliac disease.
The most common symptoms vary depending what type of T-cell lymphoma you have and where it develops.
Often, the first symptom of lymphoma is a painless swelling of a lymph node or a group of lymph nodes. However, some T-cell lymphomas start outside of the lymph nodes, for example in organs of the body like the skin, bone, lung, bone marrow and liver. Lymphoma that starts outside of the lymph nodes is called ‘extranodal’ lymphoma.
T-cell lymphomas often cause people to feel unwell and have night sweats, fevers and unexplained weight loss. These symptoms often occur together and are known as ‘B symptoms’.
It is important to find out exactly what type of T-cell lymphoma you have and what parts of your body are affected, so that your doctor can choose the best treatment for you.
T-cell lymphoma is diagnosed with a biopsy. A sample of tissue that is affected by lymphoma, such as a swollen lymph node, is examined by an expert lymphoma pathologist. The pathologist does tests on the tissue to find out what type of lymphoma you have.
Diagnosis of T-cell lymphomas can be difficult. A multidisciplinary team (MDT) look at different aspects of your lymphoma and agree on your diagnosis. The doctor diagnosing T-cell lymphoma takes into account:
- the appearance of the cells under a microscope
- the results of tests on the cells
- where the lymphoma is growing and what symptoms it causes.
You have other tests to find out more about your general health and to find out which parts of your body are affected by lymphoma – this is called ‘staging’. These tests usually include:
- a physical examination
- blood tests to look at your general health and your blood cell counts
- X-rays and scans, usually CT and PET scans and sometimes an MRI.
As T-cell lymphomas are rare and diagnosis is difficult, your doctor might consult other centres that have expertise in T-cell lymphoma. In some cases, your doctor might refer you to one of those centres.
There are 4 stages of lymphoma. Stage 1 and 2 lymphomas are described as ‘early’ stage. Stage 3 and 4 lymphomas are described as ‘advanced’ stage.
Most people with a T-cell lymphoma have advanced stage lymphoma when they are diagnosed. As the lymphatic system is all over the body, it isn’t unusual to find that lymphoma is widespread when it is diagnosed. There are treatment options for advanced stage lymphoma.
T-cell skin (cutaneous) lymphomas are staged differently to other types of T-cell lymphoma.
There are many types of T-cell lymphoma. They each behave differently and may need different treatment.
Our individual pages for each type of T-cell lymphoma have details on symptoms and treatment for each type.
Immature T-cell lymphoma:
- T-cell lymphoblastic lymphoma or LBL.
Mature T-cell lymphomas:
- peripheral T-cell lymphoma (PTCL)
- angioimmunoblastic T-cell lymphoma (AITL)/follicular T-cell lymphoma (FTCL)
- anaplastic large cell lymphoma (ALCL)
- enteropathy-associated T-cell lymphoma (EATL)
- adult T-cell leukaemia/lymphoma (ATLL)
- extranodal NK/T-cell lymphoma, nasal type
- hepatosplenic T-cell lymphoma
- cutaneous (skin) T-cell lymphoma (CTCL).
Your prognosis (outlook) depends on the type and stage of lymphoma you have and other factors like your general health. Your doctor might refer to a prognostic score, like the International Prognostic Score (IPI), when they give you this information. Factors, like your age and test results, give different scores that are added up into an overall score. Prognostic scores help doctors to plan the best possible treatment for you.
Your doctor is best placed to advise you on your individual outlook.