Lymphoma is an umbrella term for cancer of lymphocytes, a type of white blood cell that fights infection.
Lymphocytes start in your bone marrow, then move to your lymph nodes to be trained to work within your immune system as they travel through your body to fight infection. Lymphocytes are found in your lymph nodes, thymus, bone marrow, spleen, skin, and other areas in your body.
When these cells change and grow out of control, it is called lymphoma.
Aggressive and Curable vs. Indolent and Chronic
Some types of lymphoma grow and spread fast. These are called aggressive lymphomas. They tend to be more curable. If you have an aggressive lymphoma, you will receive treatment immediately.
Other types of lymphoma grow slowly. These are called indolent lymphomas. They tend to be more chronic—a disease you’ll live with for a long time. If you have an indolent lymphoma, you might wait to start treatment while under close observation by your doctor.
Two Major Types of Lymphoma
There are two major types of lymphoma: Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). They affect different types of lymphocytes.
NHL is further categorized into more than 85 subtypes. It’s one of the most complex kinds of cancer.
The type of lymphoma you have determines which treatment you’ll follow, and it plays a part in your prognosis. In general, lymphoma is survivable.
What is Hodgkin Lymphoma?
Hodgkin lymphoma is a rare disease. About 8,500 people are diagnosed in the US each year. It’s most commonly diagnosed in early adulthood—your 20s to 30s—and late adulthood—age 55 and older.
Hodgkin lymphoma is made of Reed-Sternberg cells, named after the pathologist who first described them. These malignant cells might only make up 1–2% of a tumor, compared to 90–95% of any other cancer. This fact implies that the surrounding environment plays an important role in the cancer’s behavior.
Hodgkin lymphoma spreads in a predictable manner from one lymph node to the next by your lymphatic vessels.
About 70–80% of people with Hodgkin lymphoma are cured, something that’s celebrated as a great accomplishment in cancer medicine. If you are not cured by conventional chemotherapy, it’s possible to manage the disease for a long time.
What are the Risk Factors for Hodgkin Lymphoma (HL)?
Though the below factors increase your risk for developing Hodgkin Lymphoma, there are many patients with this cancer that have no risk factors. In addition, having these risk factors does not guarantee that you will develop Hodgkin Lymphoma. It is best to discuss with a doctor any concerns regarding your risk for lymphoma.
- Age: HL is most common in both adolescents (ages 10-19), and older adults (ages >50).
- Sex: though HL affects slightly more females than males, HL in adolescence more commonly affects males
- Weakened immune system: patients with immunodeficiencies are more likely to develop HL. Conditions that affect the immune system include but are not limited to:
- Genetic syndromes
- Viral infections: Human immunodeficiency virus (HIV), Epstein-Barr virus (EBV), infectious mononucleosis (“mono”), and Human T-cell lymphocytotropic virus (HTLV) could increase one’s risk for lymphoma.
- Solid organ transplant recipients
- Family History: patients with a first-degree relative with lymphoma are at an increased risk.
What is Non-Hodgkin Lymphoma (NHL)?
Non-Hodgkin lymphomas are one of the most common cancers diagnosed in the US each year. About 4% of cancers are non-Hodgkin lymphomas, representing about 78,000 adults and children.
Non-Hodgkin lymphomas (NHL) are a set of diverse types of lymphoma categorized by the type of cell involved, either B-cells or T-cells. Some types of NHL grow quickly and others more slowly. NHL is usually found in the lymph nodes and lymphatic tissue near your stomach and intestines or in your skin. It can affect any area of your body.
B-cell vs. T-cell Lymphoma
NHL can arise from B lymphocytes or T lymphocytes. B cells and T cells are normal parts of your immune system that work by interacting with each other. B cells are a type of white blood cell that fight bacteria and viruses by creating antibodies. T cells also help to fight infection by boosting your immune system’s reaction to infections.
About 85% of people with lymphoma have B-cell lymphoma.
- Types of B-cell lymphoma
- Diffuse large B-cell lymphoma
- Follicular lymphoma
- Chronic lymphocytic leukemia/small lymphocytic leukemia
- Mantle cell lymphoma
- Marginal zone lymphoma
- Burkitt lymphoma
- Lymphoplasmacytic lymphoma (Waldenstrom macroglobulinemia)
- Primary mediastinal large B-cell lymphoma
- Types of T-cell lymphoma
- Peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS)
- Cutaneous T-cell lymphoma
- Adult T-cell leukemia/lymphoma
- Angioimmunoblastic T-cell lymphoma
- Extranodal natural killer/T-cell lymphoma, nasal type
- Enteropathy-associated intestinal T-cell lymphoma (EATL)
- Anaplastic large cell lymphoma (ALCL)
What are the risk factors for Non-Hodgkin Lymphoma?
If you’re diagnosed with lymphoma, it’s not your fault. Most lymphomas are caused by risk factors that are out of your control.
Although it is not known yet what directly causes non-Hodgkin lymphoma, the following are considered risk factors.
- Sex: NHL is more commonly found in men.
- Age: Most cases occur in people 60 and older.
- Environmental causes. Exposure to high levels of radiation, to benzene, and to some chemicals used in the petroleum and rubber industries have been linked to lymphoma.
- Previous cancer treatment: People who have received chemotherapy or radiotherapy are at increased risk for developing lymphoma.
- Family history: If you have a first-degree relative who has been diagnosed with lymphoma, your risk may be higher.
- Chronic viral infections: These include Epstein-Barr virus, human immunodeficiency virus (HIV), and human T-lymphotropic virus (HTLV).
- Weakened immune system: Illnesses that weaken your immune system, such as HIV/AIDS, and use of chronic immunosuppressive therapies can increase your risk of non-Hodgkin lymphoma.
- Autoimmune disorders People with rheumatoid arthritis, celiac disease, and lupus may have a higher risk of NHL.
What are the Symptoms of Lymphoma?
Lymphoma can present in many different ways. Some people with lymphoma have many symptoms. Others have a few, or even none at all.
Sometimes the first sign of lymphoma is painless, swollen lymph nodes in your neck, armpits, or groin.
Some people have systemic symptoms like fevers, fatigue, unexplained weight loss, drenching night sweats, and itching without a rash.
Some people have local symptoms like a cough, feeling full, a rash, brain and nerve issues like seizures, or swelling in your arms and legs.
These symptoms do not always mean that you have lymphoma. However, if you have any of these symptoms, it’s important to schedule a visit with your doctor.
Many people are diagnosed with lymphoma after seeing a primary care physician. Your doctor will most likely check for swollen lymph nodes or a swollen spleen. To determine if you have lymphoma, you may have these tests ordered by your doctor. These tests are determined by your doctor depending on the symptoms presented and findings during your exam.
- A complete blood count (CBC) gives your doctor a profile of your blood. They may also check to see how well your liver and other organs are working.
- Core needle biopsy involves using a thin needle to take tissue samples from a swollen lymph node. An exclusion biopsy could also be performed by a surgeon to ensure that there is enough material to make a diagnosis. A special type of pathologist called a hematopathologist will look for changes in the cells to determine whether you have lymphoma, and if so, what type of lymphoma you have.
- Bone marrow aspiration or biopsy uses a needle to sample marrow fluid (aspiration) and/or solid bone marrow tissue (core biopsy). This sampling usually happens at the back of your hip after numbing the area. A pathologist will then examine the cells under a microscope for abnormalities and to rule out other types of cancer.
- CT (computed tomography) scan takes data from several X-ray images and converts them into pictures on a monitor. It can show tissues and blood vessels in addition to bones.
- PET (positron emission tomography) scan uses a small amount of radioactive glucose injected into your vein to show where glucose is being used in your body. A scanner rotates around your body to create an overall picture. Cancer cells use more glucose than normal cells do.