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Non-Hodgkin lymphoma

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Primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMBCL) is a subtype of diffuse large B-cell lymphoma (DLBCL). It is also considered a distinct type of non-Hodgkin lymphoma (NHL) in the World Health Organization (WHO) classification system. It occurs in the thymus glandthymus glandThe small gland in the centre of the chest behind the breastbone (sternum) where lymphocytes (a type of white blood cell that fights germs, foreign substances or cancer cells) mature, multiply and become T cells. or lymph nodes in the centre of the chest (mediastinummediastinumThe space in the chest between the lungs, breastbone and spine that contains the heart, great blood vessels, thymus, trachea (windpipe), esophagus and lymph nodes.). This B-cell type of lymphoma is not common. It accounts for only a small number of all lymphomas. Primary mediastinal large B-cell lymphoma may also be called mediastinal B-cell lymphoma or mediastinal (thymic) large B-cell lymphoma.

Primary mediastinal large B-cell lymphoma occurs more often in adults between the ages of 30–40. It is slightly more common in women than in men.

PMBCL is usually a fast-growing (aggressive) lymphoma. People with primary mediastinal large B-cell lymphoma often have localized disease in the chest at first. It can cause shortness of breath, cough or chest pain as the tumour or mass grows in the chest. PMBCL can also partially block the main vein (superior vena cava) that carries blood from the upper body to the heart and cause superior vena cava syndrome. The bone marrow is rarely affected by this type of lymphoma.

Recurrences or relapses of PMBCL often occur in organs or tissues outside the lymph nodes (extranodal sites), such as the kidneys or central nervous systemcentral nervous systemThe brain and spinal cord, which work together to control all the functions of the body. (CNS).


Primary mediastinal large B-cell lymphoma is treated much the same as DLBCL.


Chemotherapy is often offered to treat PMBCL. A commonly used combination chemotherapy is CHOP:

  • cyclophosphamide (Cytoxan, Procytox)
  • doxorubicin (Adriamycin)
  • vincristine (Oncovin)
  • prednisone (Deltasone)

Biological therapy

Monoclonal antibodies are a type of biological therapy that is effective in treating certain types of NHL. Rituximab (Rituxan) may be added to CHOP chemotherapy (R-CHOP) to treat primary mediastinal large B-cell lymphoma.

Radiation therapy

External beam radiation therapy to the mass in the chest may be used after chemotherapy.

Stem cell transplant

A stem cell transplant (SCT) may be offered to some people with PMBCL if their lymphoma returns or relapses after treatment.

For more detailed information on specific drugs, go to sources of drug information.


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