The process for diagnosing diffuse large B-cell lymphoma (DLBCL) often requires several lab tests and a physical evaluation.

DLBCL is the most common subtype of non-Hodgkin’s lymphoma. It is an aggressive, fast-growing tumor most commonly found in the lymph nodes.

Diagnosis often involves blood draws, biopsies, a review of medical history, and other tests. An oncologist can then work with a person to determine the best treatment options for them.

Learn about the various tests and studies that a doctor may require for a DLBCL diagnosis, what the results mean, next steps, and possible treatment options.

DLBCL diagnosis often involves an oncologist. DLBCL accounts for about 25–30% of non-Hodgkin’s lymphomas, so doctors and other healthcare professionals will likely be familiar with the disease.

The presenting symptom is often a quickly growing lump or mass that may be located in a person’s armpit, neck, or groin. It may also cause symptoms that can include:

  • weight loss
  • fever
  • night sweats

DLBCL can also cause symptoms outside the lymphatic system. The most common area is the stomach or gastrointestinal tract, followed by the skin.

Additional symptoms will vary depending on the area the cancer affects. If the stomach is involved, a person may experience pain or discomfort in their abdomen, bleeding, or diarrhea.

Due to the aggressive nature of DLBCL, many people do not receive a diagnosis until later stages 3 or 4.

If a primary care physician or other healthcare professional suspects lymphoma, they should order a CT scan to check for any masses that could undergo biopsy to give a definitive diagnosis.

In addition to reviewing medical history and performing a physical examination, an oncologist will need to run several tests to diagnose DLBCL.

Lab work

Lab workups require drawing blood for examination. Several tests can help with the diagnosis, including:

  • Complete blood count: This shows the levels of different blood cells within a sample. More importantly, it can show irregularities in blood cells as well as cytopenia, such as low levels of red blood cells, white blood cells, or platelets.
  • Comprehensive metabolic profile: This shows how well the kidneys and liver are functioning and provides fluid balance and electrolyte levels.
  • Lactate dehydrogenase serology (LDS): This looks at LDS levels, an important enzyme in anaerobic metabolism.
  • Infection tests: The lab will check for different infections, including hepatitis B, hepatitis C, and HIV. Treatment often involves immunosuppression, so knowing whether a person is living with any of these viruses can affect treatment planning.

Lumbar puncture

A doctor may order this test if the person shows signs of central nervous system (CNS) involvement or is at risk of having central nervous system involvement.

People with a DLBCL diagnosis have a 5% risk of developing CNS involvement. CNS involvement is associated with a shortened life expectancy of 6 months or less, high morbidity, and fatal outcomes.

Early detection of CNS issues may help improve outcomes.

Biopsy of mass

A biopsy is a sample of tissue or cells taken from a tumor or mass. Doctors examine the sample under a microscope to check for abnormalities.

Experts recommend an excisional biopsy over a fine needle aspiration for DLBCL. Excisional biopsy means they cut through the skin to remove the entire mass. This provides more detail about the entire node.

They will also need morphology (size and shape of mass) and immunophenotyping (use of antibodies to determine the type of cell) along with staining for B cell markers to diagnose DLBCL.

Imaging tests

A doctor will likely order one of two tests to stage DLBCL. Imaging to help with staging includes PET and CT scans.

They may also use the imaging tests to check for the least invasive site to conduct a biopsy.

Current staging uses the Lugano classification system, which is based on the earlier Ann Arbor staging system. The current method breaks DLBCL into the following stages:

  • Stage 1: Involves only one lymph node region or extra lymphatic site.
  • Stage 1E: Involves a single extra lymphatic site involvement. “E” means limited extranodal involvement.
  • Stage 2: Involves two or more lymph nodes on the same side of a person’s diaphragm.
  • Stage 3: Involves lymph nodes on both sides of the diaphragm.
  • Stage 4: Occurs when the cancer spreads into one or more extra-lymphatic organs (e.g., bone, liver, lung) with or without the involvement of the lymph node.

Once results from the labs and imaging studies come back, a doctor will typically review the results with the person. Depending on the practice, this may be in person or via phone.

In some practices, a person may be able to view results through a patient portal. Once their results are available, a healthcare professional will typically contact the individual to discuss them. A doctor will likely inform the person that they have DLBCL and usually provide information about the stage, aggressiveness of the cancer, and subtype.

DLBCL can affect multiple organs and areas of the body. An oncologist will likely discuss putting together a team that may include a medical oncologist and a radiation oncologist.

They may discuss other preexisting conditions, such as HIV, that may affect treatment decisions.

The current standard of treatment is R-CHOP.

Many people with DLBCL can achieve remission with R-CHOP, which stands for:

  • R — rituximab
  • C — cyclophosphamide
  • H — doxorubicin hydrochloride (Hydroxydaunomycin)
  • O — vincristine sulfate (Oncovin)
  • P — prednisone

Rituximab is a targeted treatment using cytolytic antibodies. Prednisone is a type of steroid. The rest of the medications are chemotherapy medications.

If a person does not respond to treatment or relapses, doctors may discuss other treatment options that may include immunotherapy, other targeted therapy, or involvement in clinical trials.

Despite the success with R-CHOP, about 30–40% of people will not respond to the treatment or will relapse following initial remission.

Several factors can affect a person’s overall outlook. They include age, stage of cancer, overall health, and response to treatment.

According to the American Cancer Society, the 5-year survival rate for DLBCL is:

  • Localized: 73%
  • Regional: 74%
  • Distant: 58%
  • All SEER stages combined: 65%

These survival statistics represent the number of people still living 5 years after their diagnosis. It does not provide a specific timeline for a person and is a guide only.

An oncologist or other healthcare professional can provide a better idea of how a person will respond to treatment.

DLBCL requires lab tests, imaging, and a review of medical history for diagnosis, staging, and to help guide treatments.

Most people can fully recover with R-CHOP treatment, but some may experience remission or will not respond to treatment at all.

A person should discuss their options with an oncologist or other healthcare professional to determine the best treatments for them.