Lymph Node Biopsy
Diagnosing non-Hodgkin lymphoma (NHL) usually involves performing a lymph node biopsy. If the biopsy confirms that you have the disease, your doctor performs additional tests to stage the lymphoma.
A lymph node biopsy's purpose is to confirm a diagnosis and:
- Identify your NHL subtype
- Develop a treatment plan
Lab Tests to Confirm a Diagnosis
After your doctor takes samples of your lymph node and tissues, a hematopathologist examines them under a microscope to look for identifying characteristics of NHL. He or she confirms a diagnosis and identifies the NHL subtype. A hematopathologist is a specialist who studies blood cell diseases by looking at samples of blood and bone marrow cells and other tissues.
The hematopathologist uses one or more lab tests such as those below to examine your cells:
- Flow cytometry
- Cytogenetic analysis
- Gene expression profiling and microarray analysis
- Polymerase chain reaction (PCR)
Since NHL is a difficult disease to diagnose, you may want to get a second medical opinion by an experienced hematopathologist before you begin treatment. Some types of NHL can be confused with each other. The appropriate treatment depends on having the correct diagnosis.
Once your doctor confirms an NHL diagnosis, he or she runs more tests to stage your disease. Staging identifies the extent of your disease and where it's located in your body.
Staging tests include:
- A physical exam
- Imaging tests
- Blood tests
- Bone marrow tests
Your doctor conducts one or more imaging tests (also called diagnostic radiology), along with a physical exam, to look for:
- The location and distribution of lymph node enlargement
- Whether organs other than the lymph nodes are involved
- If there are very large masses of tumors in one site or another.
Imaging tests may include:
- Chest x-rays
- CT (computed tomography) scan
- FDG-PET (fluorodeoxyglucose (FDG) positron emission tomography) scan
- Magnetic resonance imaging (MRI)
- PET-CT scan
After your blood is taken, it's sent to a lab for a complete blood count (CBC) and more blood work. Blood tests are used to
- Determine whether lymphoma cells are present in the blood and if the special proteins (called “immunoglobulins”) made by lymphocytes are either deficient or abnormal
- Check indicators of disease severity by examining blood protein levels, uric acid levels and erythrocyte sedimentation rate (ESR)
- Assess kidney and liver functions
- Measure two important biological markers, lactate dehydrogenase (LDH) and beta2-microglobulin which are helpful prognostic indicators for several NHL subtypes
A complete blood count (CBC) may show
- Anemia (low red blood cell counts)
- Neutropenia (low levels of neutrophils, a type of white blood cells)
- Thrombocytopenia (low platelet levels)
Bone Marrow Biopsy
Most patients diagnosed with NHL undergo a bone marrow biopsy to make sure there is no spread of the disease to the bone marrow and to evaluate the use of specific therapies including radioimmunotherapy (a combination of radiation therapy and immunotherapy). A bone marrow biopsy may not always be required for patients with early-stage disease who also have low-risk features, for example, NHL with no B symptoms and no large masses.
Other Tests for Specific Subtypes
Certain tests are performed for specific subtypes only and not necessary for all patients with NHL. They include:
- Full evaluation of the gastrointestinal (GI) tract, including upper and lower endoscopies for patients who have disease involving the GI tract, such as MALT lymphoma
- Colonoscopy for patients with mantle cell lymphoma (routine colonoscopy is important for all persons beginning at age 50, or earlier if there is a family history of colon cancer)
- Testicular ultrasound for patients who have a testicular mass
- Spinal tap (lumbar puncture) and/or MRI of the brain or spinal column may be required for patients with certain subtypes or symptoms that suggest central nervous system involvement.