Because most people with lymphoma experience a variety of symptoms that may be caused by other conditions, cancer of the lymph system may be difficult to diagnose. Imaging studies include computerized tomography (CT), magnetic resonance imaging (MRI), nuclear imaging, and positron emission tomography (PET) scans.
Medical history: If lymphoma is suspected, the doctor will want to obtain a full medical history to uncover any relevant symptoms or risk factors. Medical history can contain family information, past and current health status, and past and present medications. A complete physical examination will supply other clues about possible infection, health problems, or signs of lymphoma. The physician will pay particular attention to the size, location, tenderness, and consistency (firmness) of swollen lymph nodes, and will examine external lymphatic sites for possible disease.
Complete blood counts (CBCs) are performed. A CBC evaluates certain components (parts) of blood, including hemoglobin (the oxygen-carrying protein in red blood cells), hematocrit (the proportion of red blood cells to plasma in the blood), white blood cells (which fight infection), and platelets (which help with blood clotting).
Inflammatory markers (cytokines) or enzymes (lactate dehydrogenase, or LDH) may be elevated. Normal LDH values are between one and three millimoles per liter (mmol/L). High levels of LDH in cases in which non-Hodgkin's lymphoma (NHL) is suspected may indicate a more life-threatening form of the cancer.
Biopsy: Once the doctor suspects that an individual has Hodgkin's disease (HD) or NHL, a biopsy (removal of a small amount of tissue for examination) of an enlarged lymph node is taken.
If lymphoma is diagnosed, the doctor may want to sample the bone marrow to determine the extent of disease. The bone marrow is sampled by a technique known as bone marrow aspiration. During this procedure, a thin, hollow needle with a syringe attachment is used to aspirate (suction up) a teaspoon-sized sample of liquid bone marrow from the back of the hip bone. A larger needle is then employed to obtain a bone marrow biopsy ("core" biopsy), which removes roughly a one-sixteenth inch piece of bone marrow from the hip site. The individual is generally awake during the procedure, but local anesthetics (such as lidocaine) and sedatives (such as midazolam or Versed®) may be administered. There is usually no pain involved.
Imaging studies: Imaging studies such as computed tomography (CT or CAT scan) or magnetic resonance imaging (MRI scan) can be performed to look at the size, shape, and location of lymphoma. CT scan is a computer-assisted x-ray that produces cross-sectional images of the body. Magnetic resonance imaging (MRI scan) is a technique that uses electromagnets and radio waves to create computer-generated pictures of the internal organs. CTs and MRIs are particularly useful for detecting enlarged lymph nodes or lymphoma-related abnormalities of the spleen or other organs.
Nuclear imaging scans can also be used. A gallium scan uses
the radioactive chemical gallium attached to the patient's own white blood cells. First, blood is withdrawn from the patient and sent to a nuclear pharmacy while the patient waits. The nuclear pharmacist attaches gallium to the patient's white blood cells in a test tube, and then the mixture is injected back into the patient's body. The body is then scanned with a camera from different angles to see if the gallium (attached to white blood cells) has gathered in a lymph node tumor. The small amounts of gallium used are not harmful.
The doctor may also use a lymphangiogram, or a form of x-ray in which pictures are made of the lymphatic system. The patient is injected with a special dye that helps to highlight the lymph nodes and their vessels.
Positron-emission tomographic (PET) scan may be used. PET scan is a newer alternative to lymphangiogram and gallium scans for detecting areas in the body that are affected by lymphoma. A small amount of a radioactive substance is injected into the body and then traced on the PET scan camera. Sites of radioactivity on the scan indicate areas of increased metabolic activity, which implies a tumor.
Lumbar puncture: Lumbar puncture, or spinal tap, is a procedure in which a thin needle is inserted through the lumbar (lower) backbone, below the level of the spinal cord. Cerebrospinal fluid (CSF) is withdrawn through the needle, and is then analyzed for the presence of lymphoma cells. This test is performed to see whether lymphoma has spread to the central nervous system. The procedure may be painful and requires the use of topical anesthetics such as lidocaine.
Staging and grading: Once the doctor has diagnosed lymphoma, studies to establish the patient's stage, or how far the cancer has spread, will be performed. Staging lymphoma classifies it according to size, where the cancer is, and whether and how much the cancer has spread around the body or metastasized. Determining a cancer's stage is very important because it tells the doctor which treatment is most likely to work and what the chances of remission or cure (prognosis) are.
Lymphomas are often described as being "bulky" or "nonbulky." Nonbulky means the tumor is small, while bulky means the tumor is large. Nonbulky disease has a better prognosis than bulky disease.
Grade is also an important component of the lymphoma classification and includes low-, intermediate-, and high-grade lymphoma. Low grade lymphomas grow slowly, but low-grade lymphomas are often widespread when discovered. Because they grow slowly, they usually do not require immediate treatment unless organ function is compromised. Symptoms of low-grade lymphomas include peripheral adenopathy (swelling of the lymph nodes) that is painless and slowly progressive. It is the most common clinical symptom seen in individuals with low-grade lymphoma. Splenomegaly, or enlargement of the spleen, is also seen in approximately 40% of individuals with low-grade lymphoma. B symptoms, including temperature over 100 degrees Fahrenheit, night sweats, and weight loss greater than 10% from original weight within six months, are not common initially, but are common in individuals with advanced or end-stage disease.
Intermediate grade lymphomas are rapidly growing (aggressive) lymphomas that usually require immediate treatment, but they are often curable. High grade lymphomas are very rapidly growing and aggressive lymphomas that require immediate, intensive treatment and are much less often curable. Most individuals with both intermediate- and high-grade lymphomas have adenopathy (also called lymphadenopathy, or lymph node swelling), with more than one third of individuals having lymph node involvement and swelling in the gastrointestinal (GI) tract, skin, bone marrow, sinuses, genitourinary (GU) tract, thyroid, and central nervous system (CNS).
signs and symptoms
Many individuals (up to 75% in Hodgkin's disease) do not exhibit any signs or symptoms.
Often, the first sign of lymphoma is a painless swelling in the lymph nodes of the neck, under the arms, or in the groin. The definition of an enlarged lymph node is size larger than one centimeter (0.4 inch) in diameter (pea size). Any node that is larger than one centimeter in diameter should be followed closely by a doctor. High-risk enlarged nodes are those larger than three centimeters (more than an inch) in diameter.
Lymph nodes or tissues elsewhere in the body may also swell, such as in the spleen and tonsils.
Symptoms include fever, chills, unexplained weight loss, night sweats, lack of energy, and itching. These symptoms are non-specific, meaning they could be conditions such as influenza or immune system deficiencies. Symptoms caused by these infections usually subside within two weeks, while symptoms associated with lymphomas will continue for months and even years.
risk factors and causes
The exact causes of lymphoma are not known. Several factors have been linked to an increased risk of developing lymphoma, including non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD), but it is unclear what role they play in the actual development of lymphoma. These factors are discussed below.
Age: NHLs may occur at any age, but the risk increases with age. The majority of NHLs (95%) occur in adults 40-70 years of age. However, some NHL subtypes are among the most common cancers in children, such as Burkitt's lymphoma. Hodgkin's disease (HD) usually occurs in people in their late teens or in their 60s and older. HD in the elderly is associated with a poorer prognosis than that observed in younger patients.
Infection: A number of infections by bacteria and viruses appear to increase the risk of both NHLs and HD. Individuals infected with the human immunodeficiency virus (HIV) and those having acquired immunodeficiency syndrome (AIDS), in which the immune system is progressively weakened, are at high risk for developing lymphomas. Infection with certain parasites (such as Plasmodium species) that causes malaria (found in tropical climates) or the Epstein-Barr virus (linked with mononucleosis and chronic fatigue syndrome) appears to raise the risk of a particular type of NHL called Burkitt's lymphoma. An infection with the bacterium Helicobacter pylori, which is known to cause stomach conditions such as ulcers, can cause an immune system response that raises the risk of lymphomas in the digestive system. Infection with human T-lymphocytic virus type 1 (HTLV-1), hepatitis B, or hepatitis C can also increase the chances of developing lymphomas.
Immunosuppressive therapies: Individuals taking immunosuppressive drug therapies including steroids, such as prednisone (Deltasone®), cyclosporine (Sandimmune®), methotrexate (Rheumatrex®), or azathioprine (Imuran®), may be at an increased risk for developing HD or NHLs. Immunosuppressive drugs are usually taken for conditions such as cancer, rheumatoid arthritis, and organ transplants. These drugs may alter normal immune system function and lower immunity.
Heredity: Researchers believe that activation of certain abnormal genes may be involved in the development of all cancers, including lymphomas. Evidence suggests that having a family member, such as a parent or sibling (brother or sister) may increase the chances of developing lymphomas.
Certain chemicals found in pesticide products such as lawn and garden chemicals, may increase the risk of developing lymphoma. Recent clinical studies suggest that the increased risk of pesticide exposure and NHLs may be confined to those with a history of asthma.
Long-term use of hair products, including permanent hair dyes (especially dark colors) and hair straightening chemicals, doubles an individual's risk of developing lymphoma, particularly among women and persons who used hair dyes before 1980. These dyes contained more carcinogenic (cancer-causing) substances than the dyes used today, due to changes in regulation by the U.S. Food and Drug Administration (FDA).
Early complications of lymphoma include enlarged lymph nodes, sometimes causing other symptoms by pressing against a vein or lymphatic vessel (swelling of an arm or leg), a nerve (pain, numbness, or tingling), or the stomach (early feeling of fullness). Enlargement of the spleen may cause abdominal pain or discomfort.
As the disease progresses, metastasis (spread) to other organs can result in organ damage. This can result in death. However, lymphomas are treatable if found early.