What are T-cell lymphomas?
Lymphoma is a type of blood cancer that develops when white blood cells called lymphocytes grow out of control. Lymphocytes are part of your immune system. They travel around the body in the lymphatic system, helping to fight infections. There are two types of lymphocyte: T lymphocytes (T cells) and B lymphocytes (B cells).
T-cell lymphomas are non-Hodgkin lymphomas that develop from T lymphocytes.
Some T-cell lymphomas can also develop in the skin.
T-cell lymphomas are rare and most T-cell lymphomas develop from mature T cells. They usually affect older adults, typically people in their mid-60s and are more common in men than in women. Occasionally, T-cell lymphoma can develop from immature T cells. This is known as T-cell lymphoblastic lymphoma and this type tends to affect children and young adults.
In most cases, it is not known what causes T-cell lymphomas. 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.
- Human T-lymphotropic virus type 1 (HTLV-1) is linked with development of adult T-cell leukaemia/lymphoma (ATL).
- Past infection with Epstein-Barr virus (EBV) is linked to the development of a range of lymphomas, including angioimmunoblastic T-cell lymphoma (AITL).
- Enteropathy-associated T-cell lymphoma (EATL) is linked with coeliac disease.
Remember that T-cell lymphomas are very rare and most people with these conditions do not develop lymphoma.
Symptoms of T-cell lymphomas
Symptoms of T-cell lymphomas can vary depending on the subtype of lymphoma and where in the body it develops. One of the most common symptoms of lymphoma is a swollen lymph node or nodes.
However, many T-cell lymphomas develop outside the lymph nodes or in the organs – for example, in the liver, bone marrow, gut or skin. Lymphoma that starts outside of the lymph nodes is called ‘extranodal’ lymphoma.
Extranodal lymphoma can cause many different symptoms, such as a swollen liver or spleen, a skin rash, or abnormal blood counts. These varied symptoms can make it difficult to diagnose T-cell lymphomas.
People with T-cell lymphomas often experience fevers, night sweats and unexplained weight loss. These three symptoms are known as ‘B symptoms.
Diagnosis and staging of T-cell lymphomas
T-cell lymphomas are rare and can be difficult to diagnose therefore the doctor might consult other centres that have expertise in T-cell lymphoma. In some cases, a patient may be referred to one of those centres.
It is extremely important to find out the exact type of T-cell lymphoma and what parts of the body are affected before any treatment is started. A number of different healthcare professionals may be involved in the care of the patient.
T-cell lymphoma is usually diagnosed based on a biopsy. A sample of tissue that is affected by lymphoma, such as a swollen lymph node, is removed and examined by an expert lymphoma pathologist.
Other tests to find out which areas of the body are affected by lymphoma are also done and this is called staging. Staging usually involves having a PET scan and a CT scan. Some people, particularly children, may have an MRI scan. A sample of bone marrow cells taken (a bone marrow biopsy), may also be done to check if there are lymphoma cells in the bone marrow.
As the lymphatic system is all over the body, it isn’t unusual for T-cell lymphoma to be at an advanced stage when it is diagnosed. Although this sounds alarming, there are treatment options for advanced stage lymphoma.