Mediastinal lymphoma

Mediastinal large B-cell lymphoma (MLBCL) is a rare type of non-Hodgkin lymphoma. It mainly affects young adults, and is more common in women.

MLBCL develops when the body makes abnormal B-lymphocytes – the lymphoma cells. (B-lymphocytes are white blood cells that fight infection.) The lymphoma cells start as a growth (mass) between the lungs and behind the breast bone, in an area called the mediastinum. This may cause symptoms including:

  • a cough
  • aching
  • breathlessness
  • hoarseness
  • swelling in the neck, arm and face.

To diagnose MLBCL a doctor removes some tissue from the area and checks it for lymphoma cells. You will also have tests and scans to find out whether the lymphoma has spread elsewhere. This is called staging.

MLBCL is fast-growing and needs to be treated quickly. This is usually with a combination of chemotherapy drugs and a monoclonal antibody drug called rituximab. Some people may also have radiotherapy. You may be invited to join a clinical trial looking at new ways of treating MLBCL. You can talk about this with your haematology doctor.

Mediastinal large B-cell lymphoma

Mediastinal large B-cell lymphoma is a type of non-Hodgkin lymphoma (NHL).

This section should ideally be read with our general information about NHL. We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having treatment.


Non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a cancer of the lymphatic system. The lymphatic system is made up of organs such as the bone marrow, thymus, spleen, and the lymph nodes (or lymph glands). Lymph nodes are connected by a network of tiny lymphatic vessels that contain lymph fluid. There is also lymphatic tissue in other organs, such as the skin, lungs and stomach.

There are lymph nodes all over the body. As lymph fluid flows through the lymph nodes, the nodes collect and filter out anything harmful or that the body doesn't need. This includes bacteria, viruses, damaged cells and cancer cells.

The lymphatic system
The lymphatic system

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Lymph fluid contains cells called lymphocytes. These are a type of white blood cell that help the body fight infection and disease.

Lymphocytes start to grow in the bone marrow, where blood cells are made. The two main types of lymphocytes are B-cells and T-cells. B-cells mature in the bone marrow, while T-cells mature in the thymus gland behind the breast bone. When they're mature, both B-cells and T-cells help fight infections.

Lymphoma is a disease where either T-cells or B-cells grow in an uncontrolled way. 

There are many different types of NHL. The types are grouped (or classified) according to certain characteristics, such as the type of cell involved (B-cell or T-cell). The most widely used classification system is produced by the World Health Organisation.


What is Mediastinal large B-cell lymphoma

The most common type of NHL is called diffuse large B-cell lymphoma. Mediastinal large B-cell lymphoma (MLBCL) is a rare subtype of diffuse large B-cell lymphoma. It starts as a growth (mass) in the mediastinum.

The mediastinum is an area inside the chest, between the lungs and behind the breast bone. It contains the thymus, the heart, some large blood vessels, the gullet, the windpipe, and lymph nodes.

MLBCL usually affects younger people aged 25-40, and is more common in women than in men.


Causes

The causes of MLBCL are unknown. It is not infectious and cannot be passed on to other people.


Signs and symptoms of mediastinal large B-cell lymphoma

Symptoms may be caused by the lymphoma pressing on nearby structures in the chest. This can cause a cough, aching in the chest, or breathlessness. Sometimes it may cause hoarseness. Some people develop swelling in their neck, arm and face due to the lymphoma pressing on the veins in the chest. This is known as SVCO (superior vena cava obstruction).

Other symptoms include loss of appetite and tiredness.

Some people have more general symptoms, such as night sweats, high temperatures (fevers) and weight loss. These are known as B symptoms.


How mediastinal large B-cell lymphoma is diagnosed

A diagnosis is made by removing a sample of tissue from the tumour (a biopsy) and examining the cells under a microscope.

The biopsy may be taken during a CT scan to help the doctor find the affected area. Some people will have their biopsy taken under a general anaesthetic.

If the lymph nodes in the mediastinum are the only ones affected, the biopsy is likely to be taken during a procedure known as a mediastinoscopy. The doctor makes a small cut in the chest and inserts a thin, flexible tube with a camera attached so tissue samples of the lymph nodes can be taken.

Additional tests include:

  • blood tests
  • x-rays 
  • scans
  • bone marrow biopsy 
  • heart tests, such as an ECG and an echocardiogram.

The results of these tests are used to find out more about the lymphoma and how far it has spread in the body. This information is used to help decide which treatment is most appropriate. You can read more about these tests in our information on tests for non-Hodgkin lymphoma.


Staging and grading of mediastinal large B-cell lymphoma

Staging

The stage of non-Hodgkin lymphoma describes how many groups of lymph nodes are affected, where they are in the body, and whether other organs such as the bone marrow or liver are involved. A group of lymph nodes refers to lymph nodes in one area of the body, such as in the armpit, on one side of the neck, or in the groin.

When lymphoma starts outside the lymph nodes, this is called extranodal lymphoma, and the stage will include the letter E (for extranodal).

There are four stages:

Stage 1

One group of lymph nodes is affected

Or

The lymphoma is in one area of a single organ outside the lymphatic system (called stage 1E).

Stage2

Two or more groups of lymph nodes are affected and they are either above or below the diaphragm (a sheet of muscle under the lungs that separates the chest from the abdomen)

Or

The lymphoma is in one organ or area of the body and is in lymph nodes on the same side of the diaphragm (called stage 2E).

Stage3

The lymphoma is in lymph nodes both above and below the diaphragm.

Stage 4

The lymphoma has spread to other organs, such as the bone marrow, liver, brain or the lining of the lungs (pleura).

Doctors also add the letter A or B to show whether you have any of the following symptoms: weight loss, fevers or night sweats.

If you don't have any of these symptoms, the letter A will be added next to the stage. If you do have these symptoms, the letter B is added next to the stage.

Grading

Non-Hodgkin lymphomas are divided into two groups: indolent (sometimes called low-grade) and aggressive (sometimes called high-grade). Indolent lymphomas are usually slow-growing, and aggressive lymphomas grow more quickly.

Mediastinal large B-cell lymphoma is an aggressive lymphoma. This means it is fast-growing and usually needs treatment with chemotherapy straight away.


Treatment for mediastinal large B-cell lymphoma

Chemotherapy with monoclonal antibody treatment, called immunochemotherapy, is the main treatment for mediastinal B-cell lymphoma.

Other treatments such as radiotherapy are also used. You may have a combination of different treatments.

Mediastinal large B-cell lymphoma usually responds well to immunochemotherapy, but in some people the lymphoma comes back and further treatment is needed. This may include a stem cell transplant.

Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. You will usually have a combination of different chemotherapy drugs given into the vein (intravenously), either as injections or through a drip (infusion). Your specialist will explain which combination of drugs is most appropriate for you.
A commonly used chemotherapy combination is the R-CHOP regimen. This includes the chemotherapy drugs vincristine, cyclophosphamide, doxorubicin, the steroid prednisolone, and a monoclonal antibody called rituximab (Mabthera ®).
Another chemotherapy combination that may sometimes be used is DA-EPOCH-R. This includes the chemotherapy drugs etoposide, vincristine, cyclophosphamide and doxorubicin, the steroid prednisolone, and the monoclonal antibody rituximab. ‘DA’ stands for ‘dose-adjusted’ as the dose of drugs can be adjusted depending on how your body responds to the treatment.

Monoclonal antibody therapy

Monoclonal antibodies are drugs that recognise, target and stick to particular proteins on the surface of cancer cells, and can stimulate the body’s immune system to destroy these cells

Rituximab is the main monoclonal antibody drug used to treat mediastinal large B-cell lymphoma. It's given as a drip (infusion). Rituximab is usually given with chemotherapy as part of the R-CHOP regimen.

Stem cell treatment (transplants)

Some people with lymphoma may have treatments using their own stem cells or stem cells from a donor. Stem cells are a special type of blood cell that can make all other types of blood cells.

This treatment is not suitable for everyone. It may be used if the lymphoma doesn’t respond to treatment or if it comes back after treatment. Doctors take into account a person's general health and fitness before recommending it.

Some people have some of their own stem cells collected and stored. This allows them to have higher doses of chemotherapy to destroy the lymphoma cells.

After the chemotherapy, their stem cells are returned by a drip (like a blood transfusion) to help their blood cells recover from the effects of chemotherapy.

This is called high-dose chemotherapy with stem cell support.

Some people may have treatment using stem cells from another person (a donor). This is called a donor (allogeneic) stem cell transplant.

Radiotherapy

Radiotherapy is the use of high-energy rays to destroy cancer cells while doing as little harm as possible to the healthy cells. Radiotherapy is sometimes given to the area where the lymphoma was after chemotherapy treatment.

Steroids

Steroids are often given with chemotherapy to help treat lymphomas. They can also help you feel better and reduce feelings of sickness (nausea).


Follow-up for mediastinal large B-cell lymphoma

Often scar tissue develops in the affected lymph nodes after treatment for lymphoma. The scar tissue can make it difficult to assess whether or not there are still lymphoma cells there.

A scan known as a PET scan may be used after treatment is finished to check whether there's any active lymphoma still present.


Clinical trials

New treatments for mediastinal large B-cell lymphoma are being researched all the time. Your doctor may invite you to take part in a clinical trial to compare a new treatment against the best available standard treatment. They must discuss the treatment with you and have your informed consent before entering you into a trial.

Before any trial is allowed to take place, it must be approved by a research ethics committee, which protects the interests of those taking part.

You may decide not to take part, or to withdraw from the trial at any stage. You will then receive the best standard treatment available.


Information and support

Everyone has their own way of dealing with their illness and the different emotions they experience. You may find it helpful to talk things over with family and friends or your doctor or nurse. You can also contact our cancer support specialists or the organisations below for more information and support.


Other useful organisations

The Lymphoma Association

The Lymphoma Association gives emotional support, advice and information on all aspects of Hodgkin lymphoma and non-Hodgkin lymphoma. It has a national network of people with lymphoma and local groups.

Leukaemia CARE

Leukaemia CARE is a national group promoting the welfare of people with leukaemia and other blood disorders, including non-Hodgkin lymphoma. Has regional support groups in many counties.