Lymphoma refers to cancer that starts in the lymphatic system and affects white blood cells called lymphocytes.

The lymph system is a series of lymph nodes and vessels that move lymph fluid through the body. Lymph fluids contain infection-fighting white blood cells. Lymph nodes act as filters, capturing and destroying bacteria and viruses to prevent infection from spreading.

While the lymph system typically protects your body, lymph cells called lymphocytes can become cancerous.

Lymphoma definition

Lymphoma is a general term for cancer that starts in the lymph system. There are two categories of lymphoma: Hodgkin’s lymphoma and non-Hodgkin’s lymphoma.

Under these two categories, researchers have classified more than 70 types of lymphoma. Lymphomas can affect any portion of the lymphatic system, including:

  • bone marrow
  • thymus
  • spleen
  • tonsils
  • lymph nodes

Lymphoma may not always cause symptoms in its early stages. Instead, a doctor may discover enlarged lymph nodes during a physical examination. These may feel like small, soft nodules under the skin. A person may feel the lymph nodes in the:

  • neck
  • upper chest
  • armpit
  • stomach
  • groin

Likewise, many of the symptoms of early lymphoma are not specific. That makes them easy to overlook. These common early symptoms of lymphoma include:

Because the symptoms of lymphoma are often easily overlooked, it can be difficult to detect and then diagnose it in an early stage. It’s important to know how the symptoms may begin to change as the cancer worsens.

The two major lymphoma types are Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, or NHL. A pathologist in the 1800s named Dr. Thomas Hodgkin identified the cells in what is now called Hodgkin’s lymphoma.

Those with Hodgkin’s lymphoma have large cancerous cells called Reed-Sternberg (RS) cells. People with NHL don’t have these cells.

According to the American Cancer Society (ACS), NHL is more common than Hodgkin’s lymphoma, accounting for 4 percent of all cancers.

Many lymphoma types fall under each category. Doctors call NHL types by the cells they affect, and if the cells are fast- or slow-growing. NHL forms in either the B cells or T cells of the immune system.

According to the ACS, most NHL types affect B cells. Types include:

B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most aggressive type of NHL. This fast-growing lymphoma comes from abnormal B cells in the blood. It can be cured if treated, but if left untreated, it can lead to death. The stage of DLBCL helps determine your prognosis.

T-cell lymphoma

T-cell lymphoma is not as common as B-cell lymphoma; only 15 percent of all NHL cases are this type. Several types of T-cell lymphoma exist.

Burkitt’s lymphoma

Burkitt’s lymphoma is a rare type of NHL that is aggressive and most common in people with compromised immune systems. This type of lymphoma is most common in children in sub-Saharan Africa, but it does occur in other parts of the world.

Follicular lymphoma

About 1 in 5 lymphomas diagnosed in the United States are follicular lymphoma. This type of NHL, which starts in the white blood cells, is most common in older individuals. The average age of diagnosis is 60. This lymphoma is also slow-growing, so treatments begin with watchful waiting.

Mantle cell lymphoma

This aggressive form of lymphoma is rare — only about 6 percent of NHL cases are this type. Mantle cell lymphoma is also more commonly diagnosed at a later stage, and it usually occurs in or involves the gastrointestinal tract or bone marrow.

Primary mediastinal B cell lymphoma

This subtype of B-cell lymphoma accounts for almost 10 percent of DLBCL cases. It predominantly affects women in their 20s and 30s.

Small lymphocytic lymphoma

Small lymphatic lymphoma (SLL) is a type of slow-growing lymphoma. The cancer cells of SLL are found mostly in the lymph nodes. SLL is identical to chronic lymphocytic leukemia (CLL), but with CLL, the majority of cancer cells are found in the blood and bone marrow.

Waldenstrom macroglobulinemia (lymphoplasmacytic lymphoma)

Lymphoplasmacytic lymphoma (LPL) is a rare type of cancer that accounts for just about 2 percent of all lymphomas. It mostly affects older adults. Waldenstrom macroglobulinemia is a subtype of LPL. It causes the abnormal production of antibodies.

Hodgkin’s lymphomas typically start in RS cells. While the main cause of Hodgkin’s lymphoma isn’t known, certain risk factors can increase your risk of developing this type of cancer. Hodgkin’s lymphoma types include:

Lymphocyte-depleted Hodgkin’s disease

This rare, aggressive type of lymphoma occurs in about 1 percent of lymphoma cases, and it’s most commonly diagnosed in individuals in their 30s. In diagnostic tests, doctors will see normal lymphocytes with an abundance of RS cells.

Patients with a compromised immune system, such as those with HIV, are more likely to be diagnosed with this type of lymphoma.

Lymphocyte-rich Hodgkin’s disease

This type of lymphoma is more common in men, and it accounts for about 5 percent of Hodgkin’s lymphoma cases. Lymphocyte-rich Hodgkin’s disease is typically diagnosed at an early stage, and both lymphocytes and RS cells are present in diagnostic tests.

Mixed cellularity Hodgkin’s lymphoma

Like with lymphocyte-rich Hodgkin’s disease, mixed cellularity Hodgkin’s lymphoma contains both lymphocytes and RS cells. It’s more common — almost a quarter of Hodgkin’s lymphoma cases are this type — and it’s more prevalent in older adult men.

Nodular lymphocyte-predominant Hodgkin’s disease

Nodular lymphocyte-predominant Hodgkin’s disease (NLPHL) type of Hodgkin’s lymphoma occurs in about 5 percent of people with lymphoma, and it’s characterized by an absence of RS cells.

NLPHL is most common in people between the ages of 30 and 50, and it’s more common in males. Rarely, NLPHL can progress or transform into a type of aggressive NHL.

Nodular sclerosis Hodgkin’s lymphoma

This common type of lymphoma occurs in 70 percent of Hodgkin’s cases, and it’s more common in young adults than in any other group. This type of lymphoma occurs in lymph nodes that contain scar tissue, or sclerosis.

Fortunately, this type of lymphoma is highly treatable with a high cure rate.

Lymphoma occurs when white blood cells called lymphocytes grow out of control. The average life span of a lymphocytes cell is brief, and then the cell dies. In people with lymphoma, however, DNA changes inside the lymphocytes cells cause them to thrive and spread instead of dying.

It’s unclear what exactly causes this DNA change, and even though there are some risk factors connected with lymphoma, people without the risk factors can still develop these cancers.

Most diagnosed lymphoma cases have no known cause. However, some people are considered to be at higher risk.

Non-Hodgkin’s lymphoma risk factors

Risk factors for NHL include:

  • Immunodeficiency. This could be due to a weak immune system from HIV or taking an immune system-suppressing drug after an organ transplant.
  • Autoimmune disease. People with certain autoimmune diseases, such as rheumatoid arthritis and celiac disease, have an increased risk of lymphoma.
  • Age. Lymphoma is most common in older individuals. However, some types are more common in children and infants.
  • Sex. The overall risk of NHL is higher in men than women, but there are some types of NHL that are more likely to develop in women.
  • Ethnicity. White people in the United States are more likely to develop some types of lymphoma than African Americans or Asian Americans.
  • Infection. People who have had infections such as the human T-cell leukemia/lymphotropic virus (HTLV-1), Heliobacter pylori, hepatitis C, or the Epstein-Barr virus (EBV) are associated with an increased risk.
  • Chemical and radiation exposure. Those exposed to chemicals in pesticides, fertilizers, and herbicides are also at increased risk. Nuclear radiation can also increase risks for developing NHL.
  • Body size. Individuals living with obesity may be at a higher risk of developing lymphoma, but more research is needed to understand this possible risk factor.

Hodgkin’s lymphoma risk factors

Risk factors for Hodgkin’s lymphoma include:

  • Age. More cases are diagnosed in people between the ages of 20 and 30 and in people over 55.
  • Sex. Men are more likely than women to develop this type of lymphoma.
  • Family history. If a sibling is diagnosed with this type of cancer, your risk of also developing it is higher.
  • Infectious mononucleosis. An EBV infection can cause mononucleosis. This infection can increase the risk of lymphoma.
  • Immunodeficiency. Individuals with HIV have a greater risk of developing lymphoma.

Typically, a doctor will do a biopsy if they suspect lymphoma. This involves removing cells from an enlarged lymph node. A specialist known as a hematopathologist will examine the cells to determine if lymphoma cells are present and what cell type they are.

If the hematopathologist detects lymphoma cells, further testing can identify how far the cancer has spread. These tests can include

Imaging scans, such as CT or MRI scans may also identify additional tumors or enlarged lymph nodes.

Typically, a number of medical specialists will collaborate to treat lymphoma:

  • Hematologists are doctors who specialize in blood, bone marrow, and immune cell disorders.
  • Oncologists treat cancerous tumors.
  • Pathologists may work with these doctors to assist in treatment planning and identify if a particular treatment is working.

Treatment plans depend on a few conditions, including the individual’s age and overall health, the type of lymphoma an individual has, and the cancer’s stage.

Doctors will stage a tumor to signify how far the cancerous cells may have spread. A stage 1 tumor is limited to a few lymph nodes, while a stage 4 tumor has spread to other organs, such as the lungs or bone marrow.

Doctors also grade NHL tumors by how fast they’re growing. These terms include:

  • low grade or indolent
  • intermediate grade or aggressive
  • high grade or highly aggressive

Treating Hodgkin’s lymphoma

Treatment for Hodgkin’s lymphoma usually includes radiation therapy to shrink and kill cancerous cells. Doctors may also prescribe chemotherapy medications to destroy cancerous cells.

Newer treatments also include immunotherapy therapy drugs like nivolumab (Opdivo) and pembrolizumab (Keytruda), which help the body’s T cells attack the cancer.

Treating Non-Hodgkin’s lymphoma

Chemotherapy and radiation are also used to treat NHL. Biological therapies that target cancerous B cells also can be effective. An example of this drug type includes nivolumab (Opdivo).

For some individuals, such as those with large B-cell lymphoma (DLBCL), CAR T cell therapy is part of the treatment. CAR T cell therapy uses the body’s own cells to treat the cancer: Immune cells are taken from the body, given with new proteins in a lab, and then infused back into the body.

In some instances of both Hodgkin’s lymphoma and NHL, a bone marrow or stem cell transplant may be used to build up healthy immune system cells. Doctors may harvest these cells or tissues before beginning chemotherapy and radiation treatments. Relatives may be able to donate bone marrow too.

Both NHL and Hodgkin’s lymphoma can be classified into four stages. The state of lymphoma is determined by where the cancer is and how far it has or has not spread.

  • Stage 1. Cancer is in one lymph node or one organ site.
  • Stage 2. Cancer is in two lymph nodes near to one another and on the same side of the body, or the cancer is in one organ and nearby lymph nodes.
  • Stage 3. At this point, cancer is in lymph nodes on both sides of the diaphragm.
  • Stage 4. The cancer can be in an organ and spread beyond nearby lymph nodes. As NHL progresses, it may begin to spread. The most common sites for advanced NHL include the liver, bone marrow, and lungs.

While stage 4 lymphoma is advanced, it’s still treatable.

An individual’s prognosis after a lymphoma diagnosis depends on the stage and type of lymphoma. Many types of lymphoma are treatable and highly curable.

Some types of lymphoma are also slow-growing, or indolent. In this case, doctors may choose not to treat because the prognosis, even with the lymphoma, is still good in the long term.

According to the ACS, the 5-year survival rate for stage 1 Hodgkin’s lymphoma is 91 percent; for stage 4, it’s 81 percent.

For NHL, the ACS states the 5-year survival rate is 73 percent; the 10-year survival rate is 57 percent.

Many of the same risk factors for lymphoma in children are risk factors for adults, but certain types of lymphoma are more common in children.

For example, Hodgkin’s lymphoma is more common in children ages 15 and younger, but the type of NHL that occurs in children is typically aggressive and fast-growing.

Children who have immune system deficiencies, such as HIV, or those who take immune-suppressing drugs are at an increased risk for lymphoma. Likewise, children who’ve undergone radiation therapy or chemotherapy have a higher risk of developing this type of cancer.

Both leukemia and lymphoma are types of blood cancer, and they share some common symptoms. However, their origins, treatments, and specific symptoms set the two types of cancer apart.

Symptoms

People with both lymphoma and leukemia experience fever and night sweats. However, leukemia is more likely to cause excessive bleeding, easy bruising, headaches, and increased infections. People with lymphoma are more likely to experience itchy skin, loss of appetite, unexplained weight loss, and swollen lymph nodes.

Origins

Leukemia typically begins in the bone marrow. It causes the marrow to produce too many white blood cells. Lymphoma begins in the lymph nodes, and it progresses as the abnormal white blood cells spread.

Treatment

Doctors may choose to practice watchful waiting for both lymphoma and leukemia. That’s because some types of these cancers are slow-growing and not aggressive.

If your doctor decides to treat either cancer, chemotherapy and radiation are used to treat both, but leukemia has two other common treatments. These are stem cell transplants and targeted drug therapy.

Lymphoma is a term for cancer that starts in the lymph system.

There are two overarching categories of lymphoma: Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, or NHL. Within these categories, there are more than 70 different types. Depending on the stage the cancer is discovered, the age and health of the individual, and a few other factors, many types of lymphoma are treatable and curable.

According to the Leukemia & Lymphoma Society, Hodgkin’s lymphoma is highly curable — depending on some outside factors.

According to the ACS, NHL is also treatable, with the overall 5-year survival rate for NHL patients coming in at 70 percent. The 10-year survival rate at 60 percent.

Individuals diagnosed with lymphoma often have a team of doctors behind them and a treatment plan designed for their journey.