Lymphomas are part of the general “lymphoid blood diseases” family, i.e. malignant immune system diseases. The World Health Organisation has recognised 80 sub-types, which makes diagnoses difficult, and making it necessary to provide different care for the different sub-types.
This classification is based on the aspect of the tumour (histology), the B or T type of diseased cells (the lymphoma immunological phenotype) and on genetic anomalies of the tumour cells (determined by the study of the chromosomes or genes).
Hodgkin lymphomas, or Hodgkin’s disease, represent 20 % of lymphomas. They especially affect young adults (25-30 years old), then people over 60 years old. The exact cause of this illness remains unknown.
The disease is characterised by the appearance of one or more swellings on the lymph nodes, often at the neck, and, more rarely, disorders linked to the presence of swellings on the thoracic lymph nodes or the occurrence of an unexplained fever, abundant perspiration or weight loss.
Non-Hodgkin lymphomas include all the other lymphoma types. There are various forms, depending particularly on the type of lymphocytes that are affected: B lymphocytes or T lymphocytes.
Precursor B-cell lymphoid blood diseases
- Leukaemia/B-cell lymphoblastic lymphoma
B-cell lymphoblastic lymphomas, or precursor B-cell lymphoblastic lymphomas, is a rare and aggressive type of lymphoma. The cancerous cells develop from immature B lymphocytes (lymphoblasts), mainly in the lymph nodes and bone marrow. In most cases, these are classified as leukaemia (cancers affecting the bone marrow cells) rather than lymphomas.
Mature B-cell lymphoid blood diseases
- Chronic lymphocytic leukaemia/lymphocytic lymphoma
Lymphocytic lymphoma and chronic lymphoid leukaemia are grouped into one disease. Although they are both treated the same way, the two forms have different manifestations in the organism. Lymphocytic lymphomas are characterised by the presence of cancerous cells uniquely or mainly in one or more lymph nodes. In the case of chronic lymphoid leukaemia, however, the cancerous cells are essentially present in the blood and bone marrow. This is the most frequent lymphoid blood disease among adults. It is a disease that affects those over 50 years old, and represents 6 % of all lymphomas. Its evolution is usually slow.
- Lymphoplasmacytic lymphomas
The lymphoplasmacytic lymphoma, also called Waldenström disease, referring to the Swedish doctor who first described it, is a disease that usually affects the bone marrow, the spleen and sometimes the lymph nodes. A particularity of this disease is the excess production of a type of antibody called IgM (immunoglobulin M). This antibody is then found in abnormal quantities in the blood. This is a slowly developing disease that often needs treating for several years. The treatment becomes necessary when the symptoms appear or when the quantity of immunoglobulin may represent a danger. It can transform into a large cell lymphoma.
- Splenic marginal zone lymphoma
Splenic marginal zone lymphoma is a rare lymphoma, characterised by an abnormal proliferation of mature B lymphocytes in the spleen. This disease affects not only the spleen, but also very frequently the bone marrow and nodes around the spleen. The first signs of this disease are an enlargement of the spleen (splenomegaly), often associated with a low red blood cell or blood platelet count. When the spleen becomes problematic or if the diagnosis is uncertain, a removal of the spleen (splenectomy) is often proposed. This form of lymphoma can turn into a large cell lymphoma.
- MALT lymphoma
MALT (mucosa associated lymphoid tissue) lymphomas, or MALT-like extra-nodal lymphomas are a rare form of lymphoma that develop in the lymphoid tissue associated with the mucous membranes. This type of lymphoma can affect any organ, but most frequently affects the digestive tract, especially the stomach. It can also reach the lungs or glands (lacrymal glands, thyroid, breasts). MALT lymphomas of the stomach are the most typical and the most well-known. In this form, the lymphoma is preceded by a long period of chronic stomach inflammation (gastritis), often linked to an infection by a particular germ: Helicobacter Pylori. When the lymphoma appears, it can be responsible for commonplace symptoms: stomach burns or pains. A gastric fibroscopy will reveal the lymphoma and perform biopsies. When the disease remains located in the stomach, the treatment of the Helicobacter Pylori infection often leads to the regression of the lymphoma. In other cases, chemotherapy may be necessary.
- Nodal marginal zone lymphomas
Nodal marginal zone lymphomas, sometimes called monocytoid B-cell lymphomas, are a rare form of lymphoma. It most frequently affects the nodes, but can also appear in the spleen and bone marrow. Its evolution is usually slow.
- Follicular lymphomas
Follicular lymphomas are the most common form of lymphoma. They mainly affect the nodes, but can also reach the bone marrow, the spleen, the blood, and other organs in more rare cases. By the time of diagnosis, this disease is usually already at a disseminated stage, with the stomach and thorax nodes being affected, often associated with the presence of abnormal cells in the bone marrow. However, the patients rarely present significant symptoms.
In 80 % of follicular lymphoma cases, the cancerous cells are characterised by the presence of a chromosomal anomaly that reveals a gene anomaly (the gene BCL2), leading to the appearance of the disease. It is one of the lymphomas where the choice of the therapeutic approach is the most complex, from simple observation without treatment to intensive treatments with stem cell grafts. The use of monoclonal antibodies with therapeutic aims has improved the evolution of these lymphomas. Their evolution is usually characterised by a good response to the treatments, but also by frequent relapses. Their transformation into large cell lymphomas is rather frequent after a period of several years.
- Mantle-cell lymphomas
Mantle-cell lymphomas are a quite rare form of lymphoma that affects middle-aged adults. They are characterised by the presence of cancerous cells in a specific area of the nodes or the organs called the mantle zone.
By the time of diagnosis, the disease is usually at a disseminated stage, with several node groups, and often the spleen, the bone marrow and the digestive tract being affected. Certain forms can have an aggressive evolution. Their treatment usually includes chemotherapy with a monoclonal antibody, then a therapeutic intensification with an autograft, for the youngest patients. These intensive treatments seem to have significantly improved the prognosis for this disease.
- Diffuse large B-cell lymphomas
Diffuse large B-cell lymphomas are the most frequent non-Hodgkin lymphomas (30 to 40 %). They may develop in adults of any age, but the average is beyond 60 years old. These lymphomas are characterised by the diffuse proliferation of the cancerous cells in the nodes or other affected organs. Extra-nodal organs are indeed very frequently affected. Isolated in 40 % of cases, it can concern any localisation: the digestive tract, skin, brain, bone, genital organs, tonsils… It usually leads to a rapidly growing tumour.
The classification includes variants and sub-types:
- Variants: Centroblastic, immunoblastic, T cell-rich, lymphomatoid granulomatosis type, anaplastic, plasmablastic.
- Sub-types: Mediastinal, primary serous, intravascular.
Diffuse large B-cell lymphomas are aggressive lymphomas with a rapid evolution. Current treatments, however, lead to recovery for 60 to 70 % of patients.
- Burkitt lymphoma / Burkitt cell leukaemia
Burkitt lymphomas, sometimes called Burkitt leukaemia, are a rare type of lymphoma with a very aggressive evolution. They include 3 different forms:
- Endemic Burkitt lymphomas are linked to the Epstein-Barr virus (EBV). This disease is currently prevalent in equatorial Africa and presents as a jaw tumour in young children.
- Sporadic Burkitt lymphomas are the most frequent form among children. They can affect children as well as adults, and often present as an abdominal mass that grows rapidly.
- Burkitt lymphomas associated with an immune deficiency affects patients with HIV or those having had an organ graft.
In Burkitt lymphomas, the bone marrow and nervous system can be affected. The treatment has to be started quickly. The start of the treatment may be associated with kidney complications caused by the rapid lysis of the tumour. This treatment consists of particularly intensive but short chemotherapy. Among children, the chances of recovery are particularly high.
Precursor T-cell lymphoid blood diseases
- Leukaemia/B-cell lymphoblastic lymphoma
B-cell lymphoblastic lymphomas, or precursor B-cell lymphoblastic lymphomas, is a rare and aggressive type of lymphoma. The cancer cells develop from immature T lymphocytes (lymphoblasts), mainly in the thymus and the bone marrow. This disease then manifests as an important growth between the lungs. Because the bone marrow is affected, it is often called leukaemia (a cancer that affects the bone marrow cells), more precisely acute T-cell lymphoblastic leukaemia.
Mature T-cell lymphoid blood diseases
Mature T-cell lymphomas are much more rare than B cell lymphomas. Certain forms are mainly found in certain regions of the world, and may be characterised by one organ in particular being affected. The evolution of T-cell lymphomas is usually aggressive, and aside from anaplastic lymphomas, their response to treatments is often mediocre. Below is a list of mature T-cell lymphomas:
- Leukaemia/Prolymphocytic T-cell lymphoma
- Leukaemia/Granular lymphocytic lymphoma
- Leukaemia/NK cell lymphoma
- Leukaemia/Adult T-cell lymphoma (HTLV1+)
- Mycosis fungoides / Sézary disease
- Extra-nodal T/NK cell lymphoma
- Enteropathy-associated T-cell lymphoma
- Gamma-delta T-cell lymphoma
- Subcutaneous panniculitis-like T-cell lymphoma
- Anaplastic large cell lymphoma
- Peripheral T-cell lymphomas
- Angioimmunoblastic T-cell lymphomas