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Non-Hodgkin lymphoma

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Diagnosing non-Hodgkin lymphoma

Diagnosis is the process of finding the underlying cause of a health problem. The process of diagnosis may seem long and frustrating, but it is important for the doctor to rule out other reasons for a health problem before making a cancer diagnosis. Diagnostic tests for non-Hodgkin lymphoma (NHL) are usually done when:

  • the symptoms of NHL are present, such as swollen (enlarged) lymph nodes
  • the doctor suspects NHL after talking with a person about their health and completing a physical examination
  • routine blood tests or chest x-ray suggest a problem

Many of the same tests used to initially diagnose cancer are also used to determine the stage (how far the cancer has progressed). Your doctor may also order other tests to check your general health and to help plan your treatment. Tests may include the following.

Medical history and physical examination

The medical history is a record of present symptoms, risk factors and all the medical events and problems a person has had in the past. The medical history of a person's family may also help the doctor to diagnose NHL.

In taking a medical history, the doctor will ask questions about:

  • a personal history of
    • medications or conditions that may cause a weakened immune system
      • taking immunosuppressant drugs after an organ transplant
      • HIV/AIDS
      • immunodeficiency disorders
    • autoimmuneautoimmuneA disorder in which the immune system attacks healthy tissues in the body. disorders
    • recent infections
    • previous cancer treatment
  • signs and symptoms
    • How long have the lymph nodes been swollen?
    • Has the swelling gone down after a few weeks or with antibiotics? Because swollen lymph nodes can be caused by infections, the doctor may wait a few weeks or prescribe antibiotics to see if the swelling goes down.

A physical examination allows the doctor to look for any signs of NHL. During a physical examination, the doctor may:

  • feel for any swollen or enlarged lymph nodes, including lymph nodes:
    • under the jaw and in the neck
    • in the armpit (axilla)
    • in the groin
  • examine the abdomen to check for any enlarged organs, such as an enlarged liver (hepatomegaly) or spleen (splenomegaly)
  • listen to the lungs
  • check for signs of infection that may cause lymph nodes to swell
  • check the abdomen and legs for swelling that may be caused by extra fluid if swollen lymph nodes are blocking the flow of lymph fluid
  • check for any weakness or numbness that may be caused by enlarged lymph nodes pressing against nerves or the spinal cord

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Lymph node biopsy

During a biopsy, tissue is removed from the body so it can be tested in a laboratory. The pathology report from the laboratory will confirm whether or not cancer cells are present in the sample. A lymph node biopsy is done to diagnose NHL. All or part of a lymph node may be removed. The type of biopsy done depends on where the enlarged lymph nodes are:

  • surgical biopsy – 2 types of surgical biopsies may be used
    • excisional biopsy – removes the entire lymph node and is the preferred method, whenever possible
    • incisional biopsy – removes part of the lymph node
  • core needle biopsy – removes a part of a lymph node with a hollow needle

A lymph node biopsy is the only way to make a definite diagnosis of lymphoma and to find out the subtype.

A biopsy may be taken from a lymph node in the neck, under the arm or in the groin. It may also be taken from the chest or abdomen during a computed tomography (CT) scan. If the lymph node is near the surface of the skin, the lymph node biopsy may be done with a local anesthetic. If it is deeper inside the body and not as easy to get to, the doctor may need to use a general anesthetic.

Special studies, such as molecular genetic studies, may be done on biopsy samples to help identify which lymphoma subtype a person has. Some of these techniques identify chromosomal abnormalities or genetic changes related to a lymphoma. Other studies look for certain proteins or substances on the surface of lymphoma cells.

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Bone marrow aspiration and biopsy

A bone marrow aspiration and biopsy is a procedure in which a small amount of bone marrow and bone is removed for microscopic examination. It may be used to diagnose NHL, but it is most useful for staging because NHL can spread to the bone marrow.

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Biopsies of other tissues

Lymphoma can develop in organs or tissues outside the lymph nodes (extranodal lymphoma). Biopsies of other tissues or organs may be needed to determine if lymphoma or another type of cancer is present. Sometimes these biopsies may be done to stage the lymphoma. Organs or tissues that may need to be biopsied to rule out or confirm NHL include:

  • brain
  • breast
  • skin
  • stomach
  • liver
  • intestine

Some biopsies, such as those taken from the stomach or intestine, can be done during an endoscopy procedure.

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Complete blood count

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to:

  • help rule out infection
  • assess how well the blood-forming organs (such as the bone marrow or spleen) are working and to see if lymphoma cells may have spread to the bone marrow
  • provide a baseline for future blood counts taken during and after treatment

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Blood chemistry tests

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are functioning and can also be used to detect abnormalities. They are used to help stage NHL and to check liver and kidney function.

  • Increased lactate dehydrogenase (LDH)lactate dehydrogenase (LDH)An enzyme that is involved in energy production in cells. may indicate that NHL has spread to the liver. LDH also helps determine prognosis and may influence the choice of treatment. LDH will often be higher in people with a fast-growing (aggressive) lymphoma.
  • Increased alanine aminotransferase (ALT) and aspartate transaminase (AST) may indicate liver damage from lymphoma that has spread to the liver.
  • Increased alkaline phosphatase may indicate that NHL has spread to the bone or affected the liver.

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HIV blood test

An HIV blood test may be done if doctors suspect the lymphoma is related to AIDS. This test measures the level of HIV antibodies in the blood. A high level of these antibodies means the body has been infected with HIV.

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Hepatitis B blood test

People with lymphoma are tested for hepatitis B. If they have a positive test result, they are at risk for developing hepatitis. This risk increases if they have NHL because they are likely to be treated with drugs that suppress the immune system, such as chemotherapy drugs, corticosteroids, monoclonal antibodies or radioimmunotherapy. If people test positive for hepatitis B, they are given a drug to treat hepatitis B infection while receiving treatment for NHL.

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Chest x-ray

An x-ray uses small doses of radiation to make an image of the body's structures on film. A chest x-ray is used to:

  • check for masses in the chest
  • see if NHL has spread to the lungs
  • see if there is any buildup of fluid around the lungs or heart

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Computed tomography (CT) scan

A CT scan uses special x-ray equipment to make 3-dimensional and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures. It is used to:

  • evaluate enlarged lymph nodes
  • examine organs in the:
    • chest
    • abdomen
    • pelvis
    • other areas of the body, depending on the symptoms
  • monitor response to therapy after treatment for NHL and as part of follow-up care

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Magnetic resonance imaging (MRI)

MRI uses powerful magnetic forces and radio-frequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3-dimensional pictures. It is used:

  • to check if the lymphoma has spread to the brain and spinal cord
  • if primary central nervous system (CNS) lymphoma is suspected

MRI may not be available in all treatment centres.

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Ultrasound uses high-frequency sound waves to make images of structures in the body. It is used to:

  • check if the liver or spleen is swollen or for signs of lymphoma in these organs
  • check the testicles in men with lymphoma involving the testicle
  • help doctors collect cells or tissue during a biopsy, such as a fine needle aspiration or core needle biopsy

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Lumbar puncture

A lumbar puncture (LP) involves removing a small amount of cerebrospinal fluid (CSF) from the spine for microscopic examination. It is used to:

  • find out if lymphoma from somewhere else in the body has spread to the CSF or brain
    • Doctors will do a lumbar puncture if there are neurological signs and symptoms that show lymphoma may involve the brain or if the person is at high risk for CNS involvement.
  • help diagnose primary CNS lymphoma

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Bone scan

A bone scan uses bone-seeking radioactive materials (radiopharmaceuticals) and a computer to create a picture of the bones. It is used:

  • to see if NHL has spread to the bones
  • if the person has aches and pains that may be caused by bone involvement or if alkaline phosphatase is increased

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Positron emission tomography (PET) scan

A PET scan uses radioactive materials (radiopharmaceuticals) to detect changes in the metabolic activity of body tissues. A computer analyzes the radioactive patterns and makes 3-dimensional colour images of the area being scanned. It may be used to:

  • identify areas in the body that are affected by NHL (instead of, or sometimes in addition to, a gallium scan)
  • help monitor response to treatment
  • detect recurrences

PET scans are often done instead of gallium scans to evaluate lymphoma.

The role of PET scanning in NHL is still being refined. PET scans are not available in all treatment centres.

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See a list of questions to ask your doctor about diagnostic tests.


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