Key takeaways

  • Primary mediastinal B-cell lymphoma (PMBCL) is a rare and aggressive type of non-Hodgkin’s lymphoma that originates in the white blood cells behind the breastbone.
  • Although the cause of PMBCL is unknown, it’s most commonly diagnosed in white women between the ages of 30 and 40 years old. Symptoms include chest pain, cough, and voice changes.
  • Due to its aggressive nature, PMBCL requires prompt treatment, typically a combination of immunotherapy and chemotherapy, and has a favorable outcome with a 5-year survival rate of over 80%.

Primary mediastinal B-cell lymphoma (PMBCL) is a form of non-Hodgkin’s lymphoma that starts in the B cells (white blood cells known as lymphocytes) in the area behind the breastbone. B cells are white blood cells that play an important role in the body, including controlling infections.

Sometimes called primary thymic mediastinal lymphoma, most PMBCL diagnoses are thought to start in the thymus region of the mediastinum, which lies behind the breastbone, between the lungs, and in front of the heart.

It’s a rare B-cell lymphoma subtype, but it grows quickly, typically requiring fast treatment.

PMBCL is primarily seen in white women between the ages of 30 and 40 years old and makes up approximately 5% to 10% of large B-cell lymphoma cases.

There is no known cause of PMBCL, and researchers have not identified any specific risk factors.

However, some risk factors of other non-Hodgkin’s lymphoma include:

  • immune disorders
  • obesity
  • infection
  • genetic factors
  • occupational hazards (workplace risks)

PMBCL is a specific, aggressive type of large B-cell lymphoma (LBCL).

It differs from other B-cell lymphomas because it is a large mediastinal mass with unique clinical and molecular features. Roughly 60% to 70% of the masses are greater than 10 centimeters (around 4 inches) in diameter.

While it does share B-cell markers, PMBCL differs from standard diffuse large B-cell lymphoma (DLBCL) and Hodgkin’s lymphoma, and it requires specific, tailored treatment.

In 2016, the World Health Organization (WHO) reclassified PMBCL as a distinct lymphoma type.

Some of the symptoms of PMBCL include:

  • coughing
  • aching in the chest
  • becoming out of breath
  • changes to how your voice sounds, typically a deeper, more hoarse sound
  • face, neck, or arm swelling
  • dizziness
  • headaches that can become worse when bending forward

Other symptoms may include difficulty swallowing (dysphagia), airway and blood vessel damage, and elevated lactate dehydrogenase (LDH) levels. LDH is an enzyme found throughout the body that converts glucose (sugar) into energy.

The main way to diagnose PMBCL is via different imaging methods, such as:

  • positron emission tomography (PET)
  • computed tomography (CT)
  • magnetic resonance imaging (MRI)

Doctors may perform a core needle biopsy (CNB) to help provide a more definitive diagnosis, but if possible, they may prefer a surgical biopsy procedure, which is carried out under general anesthesia.

However, a surgical biopsy may not always be the most viable option due to the possible risk of complications, especially if someone needs to begin chemotherapy quickly. Chemotherapy suppresses the body’s immune system, making healing more difficult and putting added strain on organs.

Your healthcare team will ensure you are placed at the lowest possible risk during diagnosis.

PMBCL typically requires prompt treatment due to its aggressive nature. Your healthcare team will consider various factors when deciding the best treatment options for you. This can depend on the lymphoma stage and whether you are experiencing difficult symptoms.

The current treatment recommendations are combinations of immunotherapy and chemotherapy known as chemoimmunotherapy. Examples include:

R-CHOP

This treatment is named for its drug combination of:

  • Rituximab (Rituxan): This drug is a monoclonal antibody, a type of targeted therapy. It treats some cancer types, rheumatoid arthritis (RA), and certain other conditions. It works by targeting and destroying cancer cells.
  • Cyclophosphamide: This medication belongs to a class of drugs called alkylating agents. It works by slowing the growth and spreading of some cancer cells.
  • Hydroxydaunorubicin (Doxorubicin, Adriamycin): This medication is an anthracycline antibiotic and topoisomerase inhibitor. It damages cell DNA and destroys cancer cells.
  • Vincristine sulfate (Vincasar PFS): This medication was previously sold under the brand name Oncovin, but it has now been discontinued. Its active ingredient, vincristine sulfate, prevents cancer cells from growing and dividing, and may destroy them.
  • Prednisolone: This is a steroid medication that can be used in many ways to help cancer treatment. It can help relieve nauseous feelings, prevent allergic reactions, reduce pain and swelling, and improve appetite.

DA-EPOCH-R

This is also a combination of different medications. It includes the same medications as R-CHOP but may also include etoposide.

Etoposide (VP-16) is a topoisomerase II inhibitor. It works by blocking a specific enzyme that the body needs to repair DNA and for cell division. It may also kill cancer cells.

Not everyone will have rituximab (Rituxan) with this treatment.

Many studies have shown favorable outcomes for people with PMBCL, and more than 80% of people survive for 5 years following diagnosis.

Approximately 10% to 15% of those may relapse or require further treatment.

Primary mediastinal B-cell lymphoma is a rare, serious form of non-Hodgkin’s lymphoma. This type of cancer affects the white blood cells and mainly affects white females between the ages of 30 and 40 years.

Some symptoms include coughing, chest pain, voice changes, and dizziness.

If you notice any symptoms that concern you, speak with a doctor or another healthcare professional as soon as possible. This type of cancer can advance quickly, so prompt diagnosis and treatment can give you the best chance of recovery.