Your doctor will do a physical exam first to look for signs of lymphoma. The doctor will also ask about your health history.
To confirm the presence of lymphoma, your doctor will perform a biopsy. This involves removing part or all of a lymph node or a small sample of tissue surgically or using a needle. Hematopathologists—experts in identifying blood-related cancers in biopsied tissue—look at the cells under a microscope to accurately diagnose the type of lymphoma.
Your doctor may also want you to have imaging studies, such as a chest X-ray, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scan, or positron emission tomography (PET) scan, to see pictures of the inside of your body. This allows your doctor to look for enlarged lymph nodes, tumors, or areas of cancer activity.
- Ultrasound—A small, microphone-like instrument called a transducer is placed on your skin. It emits sound waves and picks up the echoes as they bounce off the organs. The echoes are converted by a computer into an image of internal organs or tumors that is displayed on a computer screen.
- MRI—A magnet connected to a computer uses radiofrequency waves to make detailed pictures of areas inside the body.
- CT scan—An X-ray machine linked to a computer creates a series of detailed pictures of areas inside the body.
- PET scan—A scanner checks the body after an injection of a small amount of radioactive material that may collect in cancer cells.
To detect whether the cancer has spread around the lymph system or to the bone marrow or other areas, you may need these or other tests.
- Complete blood count, or CBC—This blood test is done to determine how many cells of each type are circulating in the bloodstream.
- Blood chemistry analysis—A blood sample is checked to look for chemicals that indicate disease in certain organs or tissues.
- Lumbar puncture or spinal tap—Cerebrospinal fluid is removed from the spinal column by inserting a needle between two vertebrae. The fluid is checked for cancer cells.
- Bone marrow test—In bone marrow aspiration, which usually is done first, your doctor removes a small sample of fluid bone marrow through a needle. This is followed by a bone marrow biopsy, using a needle to remove a sample of bone marrow tissue.
Tests to Classify Non-Hodgkin’s Lymphoma
If lymphoma is found, more tests may be done to identify the type of lymphoma.
- Immunohistochemistry study—This laboratory test detects specific molecules (antigens) on cells. A sample of cells is treated with special antibodies that stick to the cells only if certain antigens are present. A fluorescent dye or other substance is used to make the detected markers visible under a microscope. The type of antigen detected helps determine the subtype of lymphoma.
- Immunophenotyping—This process also uses special antibodies that bind to cells only if certain antigens are present. In flow cytometry, the cells are then passed in front of a laser beam, which gives off light if the cells have antibodies attached to them. The light can be measured and analyzed by a computer.
- Cytogenetic analysis—In this test, cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes. Lymphoma cells must grow in lab dishes for a couple of weeks before their chromosomes are ready to be viewed under the microscope. Sometimes fluorescent stains are used to help identify chromosomal changes.