How is non-Hodgkin lymphoma diagnosed?
If there is a reason to think that you may have non-Hodgkin lymphoma, your doctor will want to get a complete medical history, with information about your symptoms, risk factors, family history, and other medical conditions. Next, the doctor will do an exam, paying special attention to the lymph nodes and other places of the body that might be involved, including the spleen and liver. If you have swollen lymph nodes, the doctor will look for an infection in that area. Enlarged lymph nodes are more likely to be caused by an infection than by lymphoma.
If the doctor suspects that NHL might be causing the symptoms, he or she will recommend you have some other tests.
Imaging tests to find and stage NHL
Imaging tests are ways to take pictures of the inside of the body. These tests are used to help find a place that might be cancer, to learn how far a cancer may have spread, and to find out whether treatment is working.
An x-ray of the chest may be done to look for swollen lymph nodes in this area.
CT scan (computed tomography)
The CT scan is a special type of x-ray test that takes many pictures as it moves around the body. A computer then combines these to make a detailed picture. A CT scan is useful in looking for lymphoma in the belly (abdomen), pelvis, chest, head, and neck. CT scans can also be used to help guide a biopsy needle into a swollen lymph node.
CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. Before any pictures are taken, you may be asked to drink a liquid that helps outline the intestine for the scan. After the first set of pictures is taken, you may also get an intravenous (IV) injection of a "dye" to help outline the structures in your body. A second set of CT scan pictures is then taken. Sometimes the dye causes flushing (a feeling of warmth, especially in the face), hives, or, rarely, a serious allergic reaction like trouble breathing or low blood pressure. Be sure to tell the doctor if you have any allergies or have ever had a reaction to any contrast material used for x-rays.
MRI scan (magnetic resonance imaging)
MRI scans use radio waves and strong magnets instead of x-rays to take pictures. This test is not used as often as CT scans for lymphoma, but if your doctor is concerned about spread to the spinal cord or brain, MRI is very useful for looking at these areas. A contrast substance (called gadolinium) may be put into a vein before the scan to better show details. It is different from the dye used for CT scans, so being allergic to one doesn’t mean you are allergic to the other. Still, be sure to let the doctor know if you have had a problem with it in the past.
MRIs take longer than CT scans and you may have to lie in a narrow tube, which upsets some people. Special, open MRI machines may sometimes be an option. The drawback of the more open machines is that the pictures aren’t as clear.
The machine makes loud buzzing and clicking noises, but some places will give you earplugs or headphones to help block this out.
This test uses sound waves to make a picture of the inside of the body. It is a very easy test to have. For most scans, a kind of wand is moved along your skin over the part of your body being looked at. No radiation is used. An ultrasound can find tumors under the skin or in the belly and can show if the kidneys have become swollen because the flow of urine has been blocked by swollen lymph nodes.
PET scan (positron emission tomography)
PET scans use a form of sugar that has a radioactive atom attached to it. The sugar mixture is put into a vein and travels throughout the body. Cancer cells take up the radioactive sugar more than other cells, and then a special camera is used spot the areas of radioactivity.
PET is useful when looking for lymphoma all over the body. It can help tell whether a swollen lymph node has cancer in it. It is also used during and after treatment to find out whether an enlarged lymph node still contains cancer or just has scar tissue. For patients with lymphoma, a machine that combines the PET scan with a CT scan (PET/CT scan) is often used.
In this test a radioactive substance is put into a vein. It goes to lymph tissues in the body. A special camera is used to show these areas. This test can find tumors that might be NHL in bones and other organs. This test is not used as much now as in the past because most doctors do a PET scan instead. But it can still sometimes be useful in finding areas of lymphoma that the PET scan may miss.
For bone scans, a different radioactive substance is used. After it is put into the blood, it travels to areas of the bone that are damaged. This test is not usually done unless a person is having bone pain or has lab test results that suggest the lymphoma may have reached the bones. The scan will show bone damage caused by lymphoma, but will also pick up other problems, such as arthritis and fractures. Lymphoma in the bone can also be seen on a PET scan, so this test isn’t used if a PETscan has been done.
Tests to diagnose NHL
Lymph node biopsy
Because swollen lymph nodes are more often caused by infection, not cancer, doctors often give antibiotics and wait a few weeks to see if the nodes stay large. If the nodes stay the same or keep on getting bigger, either a small piece of the node or the whole node is often removed for testing. This is called a biopsy.
A doctor with special training (a pathologist) looks at the biopsy samples with a microscope to look for lymphoma and see what type it is. Sometimes the first biopsy does not give a final answer and another biopsy or other tests are needed.
The doctor might use other lab tests to diagnose and classify NHL such as immunohistochemistry, cytogenetics, flow cytometry, FISH, and PCR. These tests are explained in our detailed guide, Non-Hodgkin Lymphoma.
There are a few kinds of biopsies:.
- Excisional biopsy: a surgeon cuts through the skin to remove an entire lymph node (or tumor)
- Incisional biopsy: a surgeon cuts through the skin to remove only a small part of a lymph node (or tumor) (.
- Needle biopsy: a needle is used to remove part of the lymph node or tumor
Bone marrow aspiration and biopsy
NHL sometimes involves the bone marrow – the soft inner part of some bones where blood cells are made. A bone marrow aspiration and biopsy are done to check the bone marrow, often at the same time. A sample of bone marrow and a sliver of bone are removed with a large needle, usually from the back of the hip bone.
Other tests done for NHL
Lumbar puncture (spinal tap)
This test looks to see if lymphoma has spread to the tissue around the brain and spinal cord. It is not needed for most patients with lymphoma. In this test, the doctor removes a sample of the fluid around the brain and spinal cord (called cerebrospinal fluid or CSF). This is done with a needle placed between the bones of the spine into the area around the spinal cord.
Blood tests may be used to measure the amounts of certain types of cells and chemicals in the blood. They are not used to find out if a person has lymphoma, but they can be helpful in deciding how advanced the lymphoma is and how fast it is growing. Blood tests can also help find liver or kidney problems caused by either the spread of lymphoma side effects of certain chemotherapy drugs. Tests may also be done to make sure blood is clotting like it should.
Depending on what treatment you will get, your doctor may also order other blood tests to check for viral infections that may affect your treatment.
Tests of heart and lung function
These tests are not used to help find non-Hodgkin lymphoma, but they might be done if you are going to get certain chemotherapy drugs that could affect the heart or the lungs.
- Your heart function may be checked with an echocardiogram (an ultrasound of the heart) or a MUGA scan.
- Your lung function may be checked with pulmonary function tests, in which you breathe into a tube hooked up to a machine.
Last Medical Review: 08/27/2014
Last Revised: 01/06/2015