Introduction: Who Should Undergo Diagnostics

Anyone who notices unusual changes in their body that don’t go away after a few weeks should consider talking to a healthcare provider. Lymphoma, which is a cancer affecting the lymphatic system, often shows itself through symptoms that can easily be mistaken for less serious conditions. This is exactly why early diagnosis matters so much.^[1]

You should seek diagnostic testing if you have painless swelling in your lymph nodes—particularly in areas like your neck, armpits, or groin—that persists for more than a few weeks. Other warning signs include fever that stays above 103 degrees Fahrenheit for more than two days or keeps coming back, night sweats so intense that they soak your clothes and bedding, and unexplained weight loss where you’ve shed 10% of your total body weight over six months without dieting or exercising. Persistent fatigue that doesn’t improve with rest, shortness of breath, and itching without a rash are also reasons to get checked out.^[2][15]

Many of these symptoms overlap with other, less serious illnesses, so having them doesn’t automatically mean you have lymphoma. However, when these signs persist or occur together, they warrant further investigation. The earlier lymphoma is diagnosed, the more treatment options may be available and the better the potential outcomes.^[3]

Classic Diagnostic Methods

Diagnosing lymphoma is not a simple process. It involves multiple steps and often requires collaboration among several healthcare professionals, including oncologists, pathologists, and radiologists. The diagnosis must confirm not only that lymphoma is present but also determine which specific type it is, as there are more than 90 different subtypes of lymphoma.^[5]

Physical Examination and Medical History

The diagnostic journey typically begins with a thorough physical examination. Your doctor will check for swollen lymph nodes in various parts of your body, including your neck, underarms, and groin. They’ll also examine your abdomen to check if your liver or spleen is enlarged, which can happen when lymphoma affects these organs.^[2]

Your medical history is equally important. Your doctor will ask about any family history of lymphoma, as having relatives with the disease may slightly increase your risk. They’ll also inquire about past infections, particularly viruses like Epstein-Barr virus, HIV, or hepatitis, since these can increase the likelihood of developing certain types of lymphoma. Information about your occupation, exposure to chemicals like pesticides or herbicides, and any history of autoimmune diseases is also relevant.^[3][15]

Laboratory Testing

Blood tests play an important role in the diagnostic process, though they cannot diagnose lymphoma on their own. A complete blood count (CBC)—which measures the different types of cells in your blood, including white blood cells, red blood cells, and platelets—can reveal abnormalities that suggest lymphoma might be present. These tests can show if lymphoma is affecting your bone marrow’s ability to produce healthy blood cells.^[2][13]

Additional blood work typically includes tests for liver and kidney function, which help doctors understand your overall health and how well these organs are working. A test called lactate dehydrogenase (LDH) is often ordered because elevated levels can indicate more aggressive disease or greater tumor burden. Another marker called beta-2 microglobulin can provide information about prognosis.^[13]

For patients with certain types of lymphoma, particularly those related to the Epstein-Barr virus, doctors may test for EBV DNA levels in the blood. If the lymphoma is in the stomach, testing for Helicobacter pylori bacteria is routine, since this infection is linked to a specific type of gastric lymphoma.^[13]

Lymph Node Biopsy

A biopsy—the removal of tissue for examination under a microscope—is almost always necessary to definitively diagnose lymphoma. An open lymph node biopsy, where an entire lymph node or a large portion of it is surgically removed, is the preferred method. This provides pathologists with enough tissue to examine the structure of the lymph node and identify the specific characteristics of any abnormal cells present.^[5][10][14]

The tissue sample is analyzed by a pathologist who looks for specific types of abnormal cells. For Hodgkin lymphoma, the presence of unusual cells called Reed-Sternberg cells is a key diagnostic marker. If these cells are absent, the lymphoma is classified as non-Hodgkin lymphoma. The pathologist will also perform additional tests on the tissue, including examining the cells’ appearance under a microscope (morphology), identifying proteins on the cell surface (immunophenotyping), and looking for genetic or molecular changes.^[1][3]

Sometimes, a fine needle aspiration or core needle biopsy may be done first, but these methods often don’t provide enough tissue for a complete diagnosis, so an open biopsy is usually still needed.^[2]

Bone Marrow Testing

If lymphoma is confirmed, doctors often need to know if it has spread to the bone marrow. A bone marrow biopsy and aspiration involve inserting a needle into the hip bone to remove a small sample of bone marrow for examination. This test helps determine the stage of the disease—that is, how far it has spread throughout the body.^[2][13]

Imaging Studies

Once lymphoma is diagnosed, imaging tests help doctors see where in the body the disease is located and whether it has spread. Computed tomography (CT) scans use X-rays to create detailed cross-sectional images of the inside of your body. CT scans of the chest, abdomen, and pelvis are commonly used to look for enlarged lymph nodes and to check if organs like the liver or spleen are affected.^[13][14]

Positron emission tomography (PET) scans, often combined with CT scans (PET-CT), are particularly valuable for staging lymphoma. This test uses a small amount of radioactive sugar that is injected into your vein. Cancer cells, which tend to be more metabolically active than normal cells, absorb more of this sugar and “light up” on the scan. PET-CT is used to determine the extent of disease and to distinguish between aggressive and slow-growing lymphomas.^[5][14]

Magnetic resonance imaging (MRI) may be ordered if there is concern that lymphoma has spread to the brain or spinal cord. MRI uses magnets and radio waves to create detailed images of soft tissues and is particularly useful for examining the central nervous system.^[2]

For some patients, ultrasound may be used to examine specific areas, such as the abdomen or to guide needle biopsies.^[13]

Cerebrospinal Fluid Testing

For certain types of aggressive lymphoma, particularly those at higher risk of spreading to the brain and spinal cord, a lumbar puncture (spinal tap) may be performed. During this procedure, a needle is inserted into the lower back to collect a small amount of cerebrospinal fluid. This fluid is then examined for the presence of lymphoma cells.^[13]

Additional Specialized Tests

Depending on the suspected type of lymphoma, additional tests may be needed. For example, if gastric lymphoma is suspected, an endoscopy—where a thin tube with a camera is inserted through the mouth to examine the stomach—may be performed along with biopsies of the stomach lining.^[13]

Genetic and molecular testing of lymphoma cells can identify specific chromosomal abnormalities or gene mutations. These findings help classify the lymphoma more precisely and can provide information about prognosis and treatment options. For instance, certain genetic changes are characteristic of specific lymphoma subtypes, such as the t(14;18) translocation in follicular lymphoma or the t(8;14) translocation in Burkitt lymphoma.^[8]

Diagnostics for Clinical Trial Qualification

Clinical trials are research studies that test new treatments or new ways of using existing treatments. They offer patients access to cutting-edge therapies and contribute to advancing medical knowledge. However, to participate in a clinical trial, patients must meet specific eligibility criteria, which are established through diagnostic testing.^[11]

Standard Staging and Classification

Before enrolling in a clinical trial, precise staging of the lymphoma is essential. The Lugano classification system is commonly used for staging lymphoma. It incorporates information from PET-CT scans to determine the extent of disease throughout the body. The staging system categorizes lymphoma into stages I through IV, based on how many lymph node regions are involved, whether the disease is on one or both sides of the diaphragm, and whether it has spread to organs outside the lymphatic system.^[5][14]

The classification also takes into account the presence of “B symptoms”—fever, night sweats, and significant weight loss—which indicate more advanced or aggressive disease. These symptoms are noted in the staging designation (for example, stage IIB would indicate stage II disease with B symptoms).^[5]

Performance Status Assessment

Clinical trials often require patients to have a certain level of physical functioning. This is typically measured using standardized scales that assess how well you can perform daily activities and how much the disease affects your overall ability to function. Your healthcare team will evaluate whether you can participate in normal activities, whether you’re able to work, and how much time you spend resting during the day.^[12]

Organ Function Tests

Many clinical trials require that participants have adequate organ function, particularly of the liver, kidneys, heart, and lungs. This is because some investigational treatments can put additional stress on these organs, and patients with compromised organ function may be at higher risk for serious side effects.^[13]

Blood tests measuring liver enzymes, bilirubin, and creatinine help assess liver and kidney function. Tests like echocardiograms or electrocardiograms (EKGs) may be done to evaluate heart function, especially if the trial involves drugs that can affect the heart. Pulmonary function tests measure how well your lungs are working.^[13]

Molecular and Genetic Profiling

Some clinical trials are designed for patients whose lymphoma has specific genetic or molecular characteristics. For example, trials testing targeted therapies may only enroll patients whose tumors express certain proteins or harbor particular genetic mutations. This requires specialized testing of biopsy tissue using techniques like immunohistochemistry (which identifies specific proteins), fluorescence in situ hybridization (FISH, which detects chromosomal abnormalities), or next-generation sequencing (which identifies genetic mutations).^[3]

Prior Treatment History

Clinical trial protocols typically specify whether participants must be newly diagnosed (treatment-naïve) or whether they must have received and not responded to previous treatments (relapsed or refractory disease). Documentation of prior therapies, including the types of treatment received, doses, duration, and response, is required for trial eligibility assessment.^[12]

Infectious Disease Screening

Many trials require screening for infectious diseases such as HIV, hepatitis B, and hepatitis C. This is because these infections can affect the immune system and may influence how patients respond to treatment or their risk of complications. In some cases, patients with certain infections may still be eligible for trials but may need additional monitoring or antiviral therapy.^[13]

Pregnancy Testing

For women of childbearing potential, pregnancy testing is typically required before enrollment in clinical trials, as many cancer treatments can harm a developing fetus. Contraception is usually required during trial participation.^[12]