What Is Diffuse Large B-Cell Lymphoma?

Diffuse large B-cell lymphoma (DLBCL) is a cancer of the B cells of the lymphatic system. B cells are responsible for producing antibodies, which are highly specific proteins that fight against bacterial and viral infections.

When cancer develops in the B cells, it is called a B-cell lymphoma. B-cell lymphoma is a type of non-Hodgkin's lymphoma. DLBCL is the most common type of lymphoma in the United States.

This article will review the causes and symptoms of DLBCL, how it is diagnosed and treated, and its prognosis. 

Causes

The exact cause of DLBCL is often unknown, but research is ongoing. Normal cells have a predictable growth pattern of cell division. When the DNA in these cells becomes abnormal (the genes develop a mutation), it can affect how the cells grow and reproduce. Genetic mutations in B cells can result in DLBCL.

Symptoms

A variety of symptoms is associated with DLBCL. These symptoms can include:

• Enlarged lymph nodes (felt as lumps under the skin found in the neck, armpit, and groin)
• Fever
• Chills
• Drenching night sweats
• Unintentional weight loss
• Shortness of breath
• Bleeding or easy bruising
• Frequent infections
• Feeling very tired

Diagnosis

There are many steps to the process of diagnosing DLBCL. These steps include a physical examination, blood testing, imaging tests, and a biopsy. 

Physical Examination

During an examination, your healthcare provider will look for the presence of abnormal-appearing lymph nodes or anything else that looks abnormal. There will also be an evaluation of your history to see if there are any risk factors present.

Blood Tests

Blood tests that may be requested can include:

• Complete blood count (CBC) to evaluate the number of white blood cells, red blood cells, and platelets
• Complete metabolic panel (CMP) to evaluate liver and kidney function and electrolytes
• Lactic dehydrogenase (LDH), a measure of tissue damage that is often elevated with lymphoma
• Hepatitis panel to evaluate for the presence of current hepatitis infection or previous exposure
• HIV (human immunodeficiency virus) testing as some of the symptoms of an active HIV infection are similar to lymphoma symptoms

Imaging

Imaging studies are done to determine where the cancer is located in the body. This can be done usually with a computed tomography (CT) scan or a positron-emission tomography (PET) scan.

The scans are similar in that they both evaluate anatomy and can look for the presence of anything abnormal. However, a PET scan can also show metabolic activity. When cells are metabolically active, they are growing quickly and may be lymphoma cells.

During a PET scan, a special tracer attached to a sugar is injected before the scan. The sugar and tracer are taken up by the lymphoma cells (and other actively growing cells). On the scan, they appear bright. The brighter the color, the more active the cells are in that location.

Biopsy

Ultimately, a biopsy is performed. During a biopsy, tissue from an abnormal lymph node is removed and evaluated in a lab. An excisional biopsy that removes the entire lymph node is the most accurate type of biopsy to diagnose DLBCL.

Other types of biopsies include a fine needle aspiration, in which a thin needle is inserted into a lymph node to remove cells, or a core biopsy, in which a larger portion of the lymph node is removed.

A bone marrow biopsy may also need to be done. During a bone marrow biopsy, a sample of bone and bone marrow is removed, usually from the hip bone. These samples are tested to see if lymphoma cells are present in the bone marrow.

When the lymph node is found to have DLBCL, often more in-depth molecular testing is done on the sample to see if certain features are present. The presence or absence of certain molecular features can help the oncologist (cancer specialist) determine the best course of treatment. It can impact prognosis as well.

Treatment

The exact treatment for DLBCL depends on the stage of the cancer, meaning how far it has progressed, and if it is located only within the lymph system or has moved into other organs. Stages range from 1 to 4, with 4 meaning lymphoma has spread into distant parts of the body.

Many treatment options are available for DLBCL, and multiple treatments may be combined. These treatment options can include:

• Chemotherapy 
• Immunotherapy
• Targeted therapy
• Radiation therapy
• Stem cell transplant

Chemotherapy

The purpose of chemotherapy is to give medications that stop cells as they divide, effectively killing them. For DBCLC, chemotherapy consists of multiple medications given in cycles every few weeks.

The medical oncologist will recommend the exact chemotherapy regimen. It will be based on multiple factors, including the stage of the lymphoma and any genetic mutations it may have.

A common chemotherapy regimen for DLBCL is called CHOP and consists of the medications cyclophosphamide, doxorubicin, vincristine, and prednisone.

Immunotherapy

With immunotherapy, the body’s own immune system is used to kill the lymphoma cells.

In one immunotherapy treatment, CAR T-cell therapy, blood is taken from a patient and sent to a special laboratory where the T cells, important immune system cells, are removed. The T cells are then changed to allow them to attack the cancer. These T cells are then infused back into the patient.

Targeted Therapy

Monoclonal antibodies can target specific proteins on the outside of lymphoma cells. These allow for more selective destruction of lymphoma cells vs. chemotherapy, which isn’t as selective.

Monoclonal antibodies, such as Rituxan (rituximab), are often used in combination with chemotherapy to treat DLBCL.

Radiation Therapy

Radiation uses beams of high energy directed at certain areas of the body to kill cancer cells. It can be particularly useful if there is an area where lymphoma is causing significant symptoms, including pain. Radiation treatment to the entire body may also be used before stem cell transplant.

Stem Cell Transplant

A stem cell transplant is most often done when lymphoma doesn’t respond to other treatments. During a stem cell transplant, blood-producing stem cells (cells that have the potential to develop into all types of cells) are removed from the patient, or are obtained from a donor. High doses of chemotherapy, possibly along with whole-body radiation, are given to kill any lymphoma cells. 

The stem cells are then infused back into the patient to allow recovery of blood cells after the intense therapy.

Prognosis

DLBCL is usually considered to be curable, especially if it is found when locally advanced, meaning that it hasn’t spread to distant areas of the body. Even if it has spread, it may still be cured.

At diagnosis, an International Prognostic Index score may be given, which helps to determine prognosis (likely outcome). This score takes into account various characteristics of the lymphoma, as well as the age and functional status of the patient. The lower the score, the more likely they will be cured.

What to Expect

After a diagnosis of DLBCL, it can be an overwhelming and stressful time, and you will likely have many questions for your oncologist.

The treatments for DLBCL can come with side effects, especially chemotherapy, which is usually given every few weeks for a period of several months. Some of the side effects that can be experienced with chemotherapy include:

• Low blood counts
• Poor appetite
• Hair loss
• Nausea or vomiting
• Flu-like symptoms

The treatment plan for each individual may be a little different, so the cancer team should review the plan with you and any specific side effects you may experience. They should also be able to tell you the exact length of time your treatment will run.

These treatments are not often painful, but frequent lab draws and infusions may be a little uncomfortable.

Finding a support system is important when going through treatment for DLBCL. This diagnosis can spark many different feelings and emotions, and having people to talk to when they arise can be helpful. 

Some people find support groups helpful, while others may rely on support from their family, friends, or church. Talk to your cancer care team to help find resources in your area. 

Summary

DLBCL is a cancer of the B cells in the lymphatic system. The exact cause often is unknown.  Symptoms of DLBCL can include swollen lymph nodes, weight loss, and drenching night sweats. It is diagnosed through imaging studies and, ultimately, a biopsy. 

Treatment options can include chemotherapy, radiation, targeted therapy, immunotherapy, or a stem cell transplant.

A Word From Verywell

Getting a diagnosis of lymphoma can be a very uneasy and stressful time. Find a cancer care team that you feel comfortable with. Stay informed on your options for treatment and the side effects those treatments may bring. Keep a list of questions to ask your cancer care team, so that you will feel comfortable as you go through treatment.