Diagnosing non-Hodgkin lymphoma

Non-Hodgkin lymphoma is a type of white blood cell cancer. It originates in white blood cells called lymphocytes, which are part of the immune system. There are several types of non-Hodgkin lymphomas, also known as NHL. Non-Hodgkin lymphomas are more common in adults than children and may start in any part of the body where lymph tissue is found, including the lymph nodes, bone marrow and spleen.

This overview will cover the basic facts about diagnosing non-Hodgkin lymphoma, including:

• Medical evaluation
• Biopsy
• Imaging tests
• Lab tests
• Lumbar puncture

Medical evaluation

Patients may first visit their doctor because they’ve noticed a lump in their body or other unexplained symptoms, including not feeling well. If the doctor suspects that the patient has lymphoma, he or she may perform a medical evaluation, taking details on the patient’s full medical history and a physical exam. As part of the medical history, patients should be open about their risk factors, symptoms and any pre-existing medical conditions they may have.

During the physical exam, a doctor may check for swollen lymph nodes and check the spleen and liver.

A thorough and accurate cancer diagnosis is the first step in developing a non-Hodgkin lymphoma treatment plan. A multidisciplinary team of lymphoma experts uses a variety of tests and tools designed for diagnosing non-Hodgkin lymphoma, evaluating the disease, and developing each patient’s individualized treatment plan. Throughout treatment, the patient’s care team will use imaging and laboratory tests to track the size of the tumors, monitor the patient’s response to treatment, and modify the treatment plan when needed.

Biopsy

A biopsy is the only test that can definitively diagnose non-Hodgkin lymphoma. Biopsies may be used to determine the  of lymphoma, the growth rate of the tumor, and whether the disease has spread. Types of biopsies include:

Bone marrow biopsy

A bone marrow biopsy uses a needle to remove a solid sample of bone marrow from the bone. Before the procedure, local anesthetic is injected to numb the area. A bone marrow biopsy is often combined with a bone marrow aspiration, which uses a smaller needle to remove a liquid sample of bone marrow.

Lymph node biopsy

During a lymph node biopsy, all or part of a lymph node is removed.

• If an entire lymph node is removed, the procedure is considered an excisional biopsy.
• When only a portion of a lymph node is removed, the procedure is called an incisional biopsy.

Both are performed via a surgical incision in the skin. Depending on the location of the biopsy, either local or general anesthesia will be used prior to the procedure.

Fluid sampling

If the patient’s care team thinks lymphoma has spread to the chest or abdomen, fluid sampling may be performed.

• The procedure for collecting fluid from the area surrounding the lungs is called thoracentesis.
• The procedure for collecting fluid from the abdominal area is called paracentesis.

In both instances, local anesthetic is given before a needle is used to perform the sampling.

Imaging tests

The following imaging tests may be used to help diagnose non-Hodgkin lymphoma:

• X-ray: With a chest X-ray, doctors may look for enlarged lymph nodes in the chest area.
• CT scan: A computed tomography (CT) scan takes detailed pictures of inside the body and is useful for looking for signs of lymphoma in areas such as the head, chest, neck, pelvis and abdomen. CT scans are also diagnostic tools that help doctors perform a more accurate biopsy by guiding the needle to the appropriate part of the body.
• PET/CT scan: A PET scan may be combined with a CT scan, which is a way of looking for lymphoma within the body.
• MRI: Magnetic resonance imaging (MRI) is a tool used to take images of soft tissue. Although not often used for lymphomas, it may be used if there’s a possibility that the disease has spread to the brain or spine.
• Ultrasound: Ultrasounds use sound waves to take images of internal areas of the body to identify lymph nodes and examine certain organs for the presence of cancer.
• MUGA scan: A multiple-gated acquisition (MUGA) scan measures the amount of blood pumped by the patient’s heart to monitor heart health before and after treatment.

Lab tests

The care team may use various diagnostic lab tests for non-Hodgkin lymphoma to plan and monitor treatment, including:

• A flow cytometry test for non-Hodgkin lymphoma that may provide insight into whether tumor cells contain a normal or abnormal amount of DNA and determine the rate at which the tumor is growing.
• Blood and urine tests to rule out an infection or other disease and determine whether the lymphoma has spread.
• Liver function tests to measure the amounts of certain substances, such as lactate dehydrogenase, the liver has released into the blood.
• Chromosome tests, such as a fluorescent in situ hybridization (FISH) test and polymerase chain reaction (PCR) test, look for abnormalities in the body’s chromosomes (made up of proteins and DNA), which may help diagnose the type of lymphoma.

Lumbar puncture

The care team may perform a lumbar puncture, also called a spinal tap, to determine the extent of non-Hodgkin lymphoma. Lumbar punctures may also be used to inject medications, such as chemotherapy drugs, to treat the disease.

Next topic: How is non-Hodgkin lymphoma treated?