Lymphoma - Non-Hodgkin: Diagnosis

Approved by the Cancer.Net Editorial Board, 12/2016

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. To see other pages, use the menu.

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it represents disease dissemination, which is similar to “metastasis” in other forms of cancer.   For example, imaging tests can show if the cancer has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know whether an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

This list describes options for diagnosing NHL. Not all tests listed below will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of lymphoma suspected

  • Your signs and symptoms

  • Your age and medical condition

  • The results of earlier medical tests

To determine if a person has NHL, the doctor will first take a complete medical history. He or she will also do a physical examination, paying special attention to the lymph nodes, liver, and spleen. The doctor will also look for signs of infection that may cause the lymph nodes to swell and may prescribe an antibiotic. If the swelling in the lymph nodes still does not go down after antibiotic treatment, the swelling may be caused by something other than an infection. If the doctor suspects lymphoma, he or she will recommend a biopsy, as well as laboratory and imaging tests.

In addition to a physical examination, the following tests may be used to diagnose and manage NHL:

  • Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definitive diagnosis and find out the subtype. This tissue may be removed using a fine needle, a core biopsy needle, or surgery. To diagnose lymphoma, tissue is usually taken from the lymph nodes in the neck, under an arm, or in the groin. A biopsy may also be taken from the chest or abdomen using a fine needle during a computed tomography scan (CT scan) or an ultrasound (see below) or from the stomach or intestine during an endoscopy. An endoscopy is a test that allows the doctor to see inside the body with a thin, lighted, flexible tube. A biopsy of the skin may also be needed depending on which subtype of lymphoma is suspected.

    Having enough tissue in the biopsy sample is very important in making a diagnosis. Needle biopsy samples are rarely big enough to make a definite diagnosis of lymphoma. In most cases, a core biopsy or surgical biopsy is needed to correctly diagnose and classify the lymphoma. A pathologist or a hematopathologist experienced in diagnosing lymphoma then analyzes the samples. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. A hematopathologist is a pathologist who has additional training in the diagnosis of blood cancer. Because there are so many subtypes of lymphoma and because some of these subtypes are uncommon or rare, getting a second opinion that includes a formal hematopathology review of prior tissue biopsies may be helpful.

  • Computed tomography (CT or CAT) scan. A CT scan creates a 3-dimensional picture of the inside of the body using x-rays taken from different angles. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can also be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a liquid to swallow. A doctor who specializes in performing imaging tests to diagnose disease, called a radiologist, interprets CT scans. CT scans of the chest, abdomen, and pelvis can help find cancer that has spread to the lungs, lymph nodes, and liver.

  • Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can also be used to measure the tumor’s size. A special dye called contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill to swallow. A radiologist interprets the scan. 

  • Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body. A nuclear medicine physician interprets the scan.

    A doctor can use this technique to look at both the structure and how much energy is used by the tumor and healthy tissues. If, after having 1 or more imaging tests, the doctor decides the lymphoma might be affecting the bone marrow, he or she may recommend a bone marrow biopsy.

  • Bone marrow aspiration and biopsy. These 2 procedures are similar and typically done at the same time to examine the bone marrow. Bone marrow has both a solid and a liquid part. A bone marrow aspiration removes a sample of the fluid with a needle. A bone marrow biopsy is the removal of a small core of solid tissue using a needle.

    A pathologist or hematopathologist then analyzes the sample(s). A hematopathologist is a pathologist with specialized training in lymphoma, leukemia, and other blood cancers. A common site for a bone marrow aspiration and biopsy is the pelvic bone, which is located in the lower back by the hip. The skin in that area is numbed with medication beforehand. The patient may also receive other types of anesthesia to block the awareness of pain.

    Lymphoma often spreads to the bone marrow, so looking at a sample of the bone marrow can be important for diagnosing lymphoma and determining the stage. The doctor can also use the sample removed during the aspiration to find any chromosome changes.

  • Molecular testing of the tumor. Your doctor may recommend running laboratory tests on a tumor and/or bone marrow sample to identify specific genes, proteins, and other factors unique to the disease. Results of these tests will help decide whether your treatment options include a type of treatment called targeted therapy (see Treatment Options). There are different types of molecular and genetic testing:

    • Cytogenetics studies healthy and abnormal chromosomes in dividing cancer cells.

    • Fluorescent in situ hybridization (FISH) uses fluorescent probes under a special microscope to detect changes in specific chromosomes.

    • Flow cytometry looks at proteins that are on the surface or inside a cancer cell.

    • Polymerase chain reaction (PCR) detects specific DNA sequences that occur in some cancers.

    • Extended molecular profiling is used to broadly review tumor markers or to detect trace amounts of remaining cancer after treatment finishes. Although this is still being studied, it may become more commonly used in the near future.

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer. This is called subtyping and staging.

The next section helps explain the different subtypes of NHL that may be diagnosed. Or, use the menu to choose another section to continue reading this guide.