Non-Hodgkin lymphoma (NHL) is a cancer that starts in lymphocytes. Lymphocytes are cells of the lymphatic system.
The lymphatic system works with other parts of your immune system to help your body fight infection and disease. The lymphatic system is made up of a network of lymph vessels, lymph nodes and the lymphatic organs. Lymph vessels carry lymph fluid, which contains lymphocytes and other white blood cells, antibodies and nutrients. Lymph nodes sit along the lymph vessels and filter lymph fluid. The lymphatic organs include the spleen, thymus, adenoids, tonsils and bone marrow.
Lymphocytes develop in the bone marrow from basic cells called stem cells. Stem cells develop into different types of cells that have different jobs. Lymphocytes are types of white blood cells that help fight infection. There are 2 types of lymphocytes:
- B cells stay in the bone marrow until they mature
- T cells move to the thymus to mature
Lymphocytes sometimes change and no longer grow or behave normally. These abnormal cells can form tumours called lymphomas. Non-Hodgkin lymphoma can start from either B cells or T cells.
There are over 30 types of non-Hodgkin lymphoma. They are grouped based on the type of lymphocyte they started from. Most types of NHL start in B cells and are called B-cell lymphoma. NHL can also start in T cells, which is called T-cell lymphoma. The different types of NHL look different under a microscope. They also develop and grow differently. The grade of NHL is based on how different, or abnormal, the cancer cells look compared to normal lymphocytes. The grade gives doctors an idea of how slowly or quickly the lymphoma will likely grow and spread. NHL is usually divided into 2 groups:
- Low-grade, or indolent, lymphoma.
- High-grade, or aggressive, lymphoma.
Because lymphocytes are found throughout the lymphatic system, NHL can start almost anywhere in the body. It usually starts in a group of lymph nodes in one part of the body, most often in the chest or neck or under the arms. NHL usually spreads in a predictable, orderly way from one group of lymph nodes to the next. Eventually, it can spread to almost any tissue or organ in the body through the lymphatic system or the bloodstream.
Other cancers of the lymphatic system are called Hodgkin lymphoma (HL). The abnormal B cells of Hodgkin lymphoma look and behave differently from non-Hodgkin lymphoma cells. Hodgkin lymphomas and non-Hodgkin lymphomas are treated differently.
A sign is something that can be observed and recognized by a doctor or healthcare professional (for example, a rash). A symptom is something that only the person experiencing it can feel and know (for example, pain or tiredness). The signs and symptoms of non-Hodgkin lymphoma (NHL) can also be caused by other health conditions. It is important to have any unusual symptoms checked by a doctor.
Signs and Symptoms of NHL Include:
- Swollen (enlarged) lymph nodes in the neck, armpit (axilla) or groin – the most common symptom.
- Swollen lymph nodes are usually painless. However, they can eventually put pressure on surrounding tissue or organs and cause discomfort or pain..
- Swollen lymph nodes are common and can be caused by other health problems, such as an infection or the flu. However, these nodes are generally small in size. If they are swollen due to infection, the nodes may be tender or painful
- Skin rash or itchy skin (pruritus)
- Unexplained fatigue
Some symptoms of NHL are generalized and affect the whole body. These are called systemic symptoms or B symptoms and include:
- Unexplained fever – temperature over 38°C, without an obvious cause, that can last for weeks
- Drenching night sweats – so much sweat that nightwear or sheets are wet and may have to be changed
- Unexplained weight loss – loss of more than 10% of original body weight within the last 6 months
B symptoms are usually associated with more extensive disease. Their presence can play a role in treatment decisions
Signs and Symptoms According to the Location of Disease
NHL can Cause Other Signs and Symptoms Depending on the Part of the Body Affected
- NHL affecting the chest may cause
- Shortness of breath
- NHL affecting the abdomen may cause:
- A lump or swelling in the abdomen
- Abdominal tenderness, discomfort or pain
- Nausea or vomiting
- Loss of appetite
- Enlarged liver or spleen
- Anemia due to chronic bleeding in the gastrointestinal (GI) tract, such as the stomach or intestines
- NHL affecting the brain (CNS lymphoma) may cause:
- Difficulty thinking
- Trouble moving parts of the body
- Personality changes
- NHL affecting the bone marrow may cause:
- Low blood counts
- Recurring or constant infections
- Bleeding or increased bruising
Treatment for non-Hodgkin lymphoma (NHL) is given by cancer specialists (oncologists) or hematologists. Some specialize in surgery, some in radiation therapy and others in chemotherapy (drugs). These doctors work with the person with cancer to decide on a treatment plan.
Treatment plans are designed to meet the unique needs of each person with lymphoma. Treatment decisions for non-Hodgkin lymphoma (NHL) are based on:
- The type of NHL
- The stage of NHL
- How quickly the NHL is growing (grade) – whether it is slow growing (indolent) or fast growing (aggressive)
- Prognostic factors.
- A person’s age
- A person’s overall health and if they have other medical conditions that may interfere with treatment
- Previous treatment, if any
Lymphomas are Often Very Responsive to Treatment. Treatment Options for NHL
- The chemotherapy drugs used depend on the type and stage of NHL being treated
- Single chemotherapy drugs or combinations of chemotherapy drugs are often used to treat NHL
- Biological Therapy
- Biological therapy may be used on its own to treat certain types and stages of NHL. It may also be used in combination with chemotherapy.
- Radiation Therapy
- External beam radiation therapy may be used on its own to treat localized areas of early stage lymphoma. It may also be used along with chemotherapy as part of a combination of treatments.
- Watchful Waiting
- Watchful waiting is used when the lymphoma is progressing very slowly and there are no symptoms. The person is watched closely for signs or symptoms of disease progression without being given any treatment. Treatment is given when the person develops symptoms or there are signs that the lymphoma is progressing
- Surgery is mainly used to remove all or part of a lymph node (biopsy) to diagnose lymphoma. More extensive surgery is rarely used to treat NHL
- The spleen may be removed (splenectomy) in certain situations
- Stem Cell Transplant
- A stem cell transplant (SCT) may be used in certain situations, such as when the lymphoma has recurred after being treated or no longer responds to treatment
- Follow-up after treatment is finished
- It is important to have regular follow-up visits, especially during the first 2 years after treatment because that is when the risk of recurrence is greatest