Non-Hodgkin Lymphoma- definition, risk factors, symptoms, diagnosis, types, treatment,

Definition -: Any of a large group of cancers of lymphocytes (white blood cells). Non-Hodgkin lymphomas can occur at any age and are often marked by lymph nodes that are larger than normal, fever, and weight loss. There are many different types of non-Hodgkin lymphoma. These types can be divided into aggressive (fast-growing) and indolent (slow-growing) types, and they can be formed from either B-cells or T-cells. B-cell non-Hodgkin lymphomas include Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, and mantle cell lymphoma. T-cell non-Hodgkin lymphomas include mycosis fungoides, anaplastic large cell lymphoma, and precursor T-lymphoblastic lymphoma. Lymphomas that occur after bone marrow or stem cell transplantation are usually B-cell non-Hodgkin lymphomas. Prognosis and treatment depend on the stage and type of disease. Also called NHL.

Non-Hodgkin lymphoma is cancer that begins in cells of the immune system. The immune system fightsinfections and other diseases.

The lymphatic system is part of the immune system. The lymphatic system includes the following:

• Lymph vessels: The lymphatic system has a network of lymph vessels. Lymph vessels branch into all the tissues of the body.
  
• Lymph: The lymph vessels carry clear fluid called lymph. Lymph contains white blood cells, especially lymphocytes such as B cells and T cells.
  
• Lymph nodes: Lymph vessels are connected to small, round masses of tissue called lymph nodes. Groups of lymph nodes are found in the neck, underarms, chest, abdomen, and groin. Lymph nodes store white blood cells. They trap and remove bacteria or other harmful substances that may be in the lymph.
  
• Other parts of the lymphatic system: Other parts of the lymphatic system include the tonsils,thymus, and spleen. Lymphatic tissue is also found in other parts of the body including the stomach, skin, and small intestine.

Because lymphatic tissue is in many parts of the body, lymphoma can start almost anywhere. Usually, it's first found in a lymph node.

 Non-Hodgkin Lymphoma Cells

Non-Hodgkin lymphoma begins when a lymphocyte (usually a B cell) becomes abnormal. The abnormal cell divides to make copies of itself. The new cells divide again and again, making more and more abnormal cells. The abnormal cells don't die when they should. They don't protect the body from infections or other diseases. The buildup of extra cells often forms a mass of tissue called a growth or tumor.

Risk Factors

• Weakened immune system: The risk of developing lymphoma may be increased by having a weakened immune system (such as from an inherited condition or certain drugs used after an organ transplant).
  
• Certain infections:Having certain types of infections increases the risk of developing lymphoma. However, lymphoma is not contagious. You cannot catch lymphoma from another person.
  
  The following are the main types of infection that can increase the risk of lymphoma:
  • Human immunodeficiency virus (HIV): HIV is the virus that causes AIDS. People who have HIV infection are at much greater risk of some types of non-Hodgkin lymphoma.
  • Epstein-Barr virus (EBV): Infection with EBV has been linked to an increased risk of lymphoma. In Africa, EBV infection is linked to Burkitt lymphoma.
  • Helicobacter pylori: H. pylori are bacteria that can cause stomach ulcers. They also increase a person's risk of lymphoma in the stomach lining.
  • Human T-cell leukemia/lymphoma virus type 1 (HTLV-1): Infection with HTLV-1 increases a person's risk of lymphoma and leukemia.
  • Hepatitis C virus: Some studies have found an increased risk of lymphoma in people with hepatitis C virus. More research is needed to understand the role of hepatitis C virus.
  • Researchers are studying obesity and other possible risk factors for non-Hodgkin lymphoma. People who work with herbicides or certain other chemicals may be at increased risk of this disease. Researchers are also looking at a possible link between using hair dyes before 1980 and non-Hodgkin lymphoma.
    
    
    Having one or more risk factors does not mean that a person will develop non-Hodgkin lymphoma. Most people who have risk factors never develop cancer.
    
    
    Symptoms
    Non-Hodgkin lymphoma can cause many symptoms:
    • Swollen, painless lymph nodes in the neck, armpits, or groin
      
    • Unexplained weight loss
      
    • Fever
      
    • Soaking night sweats
      
    • Coughing, trouble breathing, or chest pain
      
    • Weakness and tiredness that don't go away
      
    • Pain, swelling, or a feeling of fullness in the abdomen
    Most often, these symptoms are not due to cancer. Infections or other health problems may also cause these symptoms. Anyone with symptoms that do not go away within 2 weeks should see a doctor so that problems can be diagnosed and treated.
    
    
    Diagnosis
    Types of Non-Hodgkin Lymphoma
    If you have swollen lymph nodes or another symptom that suggests non-Hodgkin lymphoma, your doctor will try to find out what's causing the problem. Your doctor may ask about your personal and family medical history.
    You may have some of the following exams and tests:
    • Physical exam: Your doctor checks for swollen lymph nodes in your neck, underarms, and groin. Your doctor also checks for a swollen spleen or liver.
      
    • Blood tests: The lab does a complete blood count to check the number of white blood cells. The lab also checks for other cells and substances, such as lactate dehydrogenase (LDH). Lymphoma may cause a high level of LDH.
      
    • Chest x-rays: You may have x-rays to check for swollen lymph nodes or other signs of disease in your chest.
      
    • Biopsy: A biopsy is the only sure way to diagnose lymphoma. Your doctor may remove an entire lymph node (excisional biopsy) or only part of a lymph node (incisional biopsy). A thin needle (fine needle aspiration) usually cannot remove a large enough sample for the pathologist to diagnose lymphoma. Removing an entire lymph node is best. The pathologist uses a microscope to check the tissue for lymphoma cells.

    Types of Non-Hodgkin Lymphoma

    When lymphoma is found, the pathologist reports the type. There are many types of lymphoma. The most common types are diffuse large B-cell lymphoma and follicular lymphoma.

    Lymphomas may be grouped by how quickly they are likely to grow:

    • Indolent (also called low-grade) lymphomas grow slowly. They tend to cause few symptoms.
      
    • Aggressive (also called intermediate-grade and high-grade) lymphomas grow and spread more quickly. They tend to cause severe symptoms. Over time, many indolent lymphomas become aggressive lymphomas.

    It's a good idea to get a second opinion about the type of lymphoma that you have. The treatment plan varies by the type of lymphoma.
    
    
    Staging
    

    Your doctor needs to know the extent (stage) of non-Hodgkin lymphoma to plan the best treatment. Staging is a careful attempt to find out what parts of the body are affected by the disease.

    Lymphoma usually starts in a lymph node. It can spread to nearly any other part of the body. For example, it can spread to the liver, lungs, bone, and bone marrow.

    Staging may involve one or more of the following tests:

    • Bone marrow biopsy: The doctor uses a thick needle to remove a small sample of bone and bone marrow from your hipbone or another large bone. Local anesthesia can help control pain. A pathologist looks for lymphoma cells in the sample.
      
    • CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of your head, neck, chest, abdomen, or pelvis. You may receive an injection of contrast material. Also, you may be asked to drink another type of contrast material. The contrast material makes it easier for the doctor to see swollen lymph nodes and other abnormal areas on the x-ray.
      
    • MRI: Your doctor may order MRI pictures of your spinal cord, bone marrow, or brain. MRI uses a powerful magnet linked to a computer. It makes detailed pictures of tissue on a computer screen or film.
      
    • Ultrasound: An ultrasound device sends out sound waves that you cannot hear. A small hand-held device is held against your body. The waves bounce off nearby tissues, and a computer uses the echoes to create a picture. Tumors may produce echoes that are different from the echoes made by healthy tissues. The picture can show possible tumors.
      
    • Spinal tap: The doctor uses a long, thin needle to remove fluid from the spinal column. Local anesthesia can help control pain. You must lie flat for a few hours afterward so that you don't get a headache. The lab checks the fluid for lymphoma cells or other problems.
      
    • PET scan: You receive an injection of a small amount of radioactive sugar. A machine makes computerized pictures of the sugar being used by cells in your body. Lymphoma cells use sugar faster than normal cells, and areas with lymphoma look brighter on the pictures.

    The stage is based on where lymphoma cells are found (in the lymph nodes or in other organs or tissues). The stage also depends on how many areas are affected. 

    
    

    Treatment

    
    

    The choice of treatment depends mainly on the following:

    • The type of non-Hodgkin lymphoma (for example, follicular lymphoma)
      
    • Its stage (where the lymphoma is found)
      
    • How quickly the cancer is growing (whether it is indolent or aggressive lymphoma)
      
    • Your age
      
    • Whether you have other health problems

    If you have indolent non-Hodgkin lymphoma without symptoms, you may not need treatment for the cancer right away. The doctor watches your health closely so that treatment can start when you begin to have symptoms. Not getting cancer treatment right away is called watchful waiting.

    If you have indolent lymphoma with symptoms, you will probably receive chemotherapy and biological therapy. Radiation therapy may be used for people with Stage I or Stage II lymphoma.

    If you have aggressive lymphoma, the treatment is usually chemotherapy and biological therapy. Radiation therapy also may be used.

    If non-Hodgkin lymphoma comes back after treatment, doctors call this a relapse or recurrence. People with lymphoma that comes back after treatment may receive high doses of chemotherapy, radiation therapy, or both, followed by stem cell transplantation.