Non-Hodgkin Lymphoma: Introduction
What is cancer?
Cancer is when cells in the body change and grow out of control. To help you understand what happens when you have cancer, let's look at how your body works normally. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them, and die when your body does not need them any longer.
Cancer is made up of abnormal cells that grow even though your body doesn't need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in your body long enough, they can grow into, or invade, nearby areas. They can even spread to other parts of your body. This is called metastasis.
What is non-Hodgkin lymphoma?
Lymphoma is a kind of cancer that starts in the lymphatic system. With non-Hodgkin lymphoma, cells in the lymphatic system grow out of control. This most often happens in the lymph nodes. The mass of extra cells form a tumor. Sometimes tumors form in the spleen or in other organs.
Understanding the lymphatic system
The lymphatic system is part of the immune system. It helps the body fight infection. It also helps maintain fluid balance in different parts of the body. The lymphatic system includes:
Lymphocytes. These are a type of white blood cell. They fight infection and disease.
Lymph. This is a clear fluid that contains lymphocytes.
Lymph vessels. These are tiny tubes. They carry lymph fluid from areas of the body back to the bloodstream.
Lymph nodes. These are small organs about the size of a pea. They are found in the underarms, groin, neck, chest, abdomen, and other parts of the body. They filter the lymph fluid as it moves around the body.
Other organs and body tissues. The lymphatic system includes the bone marrow where blood is made. And it includes the spleen, thymus, tonsils, and digestive tract.
There are 2 main kinds of lymphocytes:
B-lymphocytes (B-cells). B-cells fight germs like bacteria by making antibodies. These antibodies attach to the bacteria and attract a cell that eats the bacteria. The antibodies also attract proteins from the blood to help kill bacteria.
T-lymphocytes (T-cells). T-cells protect the body from fungi, viruses, and some bacteria. T-cells are able to find viral proteins in a virus-infected cell and then destroy the infected cell. T-cells also send out proteins called cytokines. These proteins signal other types of white blood cells to the infected area. T-cells can also kill some cancer cells.
B-cell lymphoma is much more common than T-cell lymphoma. About 85% of people with non-Hodgkin lymphoma in the U.S. have B-cell. About 15% have T-cell.
How lymphoma spreads
Lymphoma can start in any part of your lymphatic system. It can then spread to more than one area of the body. Lymphoma may also spread to the bone marrow and to other organs in the body. It can spread in different ways. It depends on the type of lymphoma and where it started growing.
Lymphoma that begins in an organ that is not a lymph node, such as the stomach, is called extranodal lymphoma. This type of lymphoma tends to spread first to the lymph nodes near that organ or to sites other than the lymph nodes.
Types of lymphoma
Non-Hodgkin lymphoma is different from Hodgkin lymphoma. With Hodgkin lymphoma, cancer cells only make up a small part of the cells in a cancerous lymph node. The rest of the cells are normal immune cells. The cancer cells are usually special cells called Reed-Sternberg cells. In non-Hodgkin lymphoma, cancer cells make up most of a tumor. There are no Reed-Sternberg cells in the tumor.
Hodgkin and non-Hodgkin lymphoma also differ in the way they spread and in how they are treated.
Lymphoma can be grouped in different ways. They can be grouped by the type of lymphocytes they start in: B-cells or T-cells. Another way to group them is based on how fast they grow, such as:
Indolent or low-grade lymphoma. These types tend to grow slowly. They tend to cause few symptoms, at least at first. These lymphomas may not need to be treated right away. And they often respond well to treatment, so people with this type can often live for a long time. But these lymphomas tend to be much harder to cure than faster-growing lymphomas.
Aggressive or high-grade lymphoma. These types tend to grow and spread quickly. They usually need to be treated right away. Even though they grow quickly, these lymphomas often respond well to treatment. Some of them may be curable.
What are the types of non-Hodgkin lymphoma?
There are many different types of non-Hodgkin lymphoma. They grow at different rates, and are treated in different ways. Finding out which type of non-Hodgkin lymphoma you have is very important in choosing the best treatment.
The common types of B-cell lymphoma include:
Diffuse large B-cell lymphoma (DLBCL). DLBCL makes up almost 1/3 of all lymphomas. It occurs mostly in people in their mid-60s. It is a fast-growing or aggressive type of lymphoma. With treatment, more than half of people with this type can be cured. The outcome or prognosis is best for people with lymphoma in only one part of the body.
Follicular or nodular lymphoma. This type makes up about 20% of all lymphomas. This is an indolent or slow-growing type of lymphoma. Most of the time, it occurs in many lymph nodes throughout the body and in the bone marrow. This lymphoma tends to grow slowly and often responds well to treatment. But it is hard to cure.
Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). These related diseases account for about 5% to 10% of all lymphomas. CLL occurs mostly in the blood and bone marrow. SLL is mainly in the lymph nodes. Both are slow-growing diseases. These lymphomas are often not curable with standard types of treatment. But most people can live with these types of lymphoma for more than 10 years.
Extranodal marginal zone B-cell lymphomas or MALT lymphomas. Marginal zone lymphomas make up about 5% to 10% of lymphomas. MALT or mucosa-associated lymphoid tissue lymphoma is a type of marginal zone lymphoma linked to an infection by Helicobacter pylori bacteria. Most MALT lymphomas begin in the stomach. They can also be found confined to sites such as the lungs, skin, thyroid or salivary glands, and tissues surrounding the eye. When it is in the stomach, this lymphoma can often be cured by giving antibiotics to kill the bacteria that cause it.
Mantle cell lymphoma. This type accounts for about 5% of lymphoma cases. Men are affected more often than women. In most cases it is in a large area, or is widespread, when diagnosed. This area may include lymph nodes, bone marrow, and often the spleen. This lymphoma does not grow very fast. But it is often hard to treat.
Primary mediastinal B-cell lymphoma. This type accounts for about 2% of all lymphomas. It is a subtype of DLBCL. Women are affected more often than men. Most are in their 30s. This lymphoma starts in the area around the heart and behind the chest bone, called the mediastinum. It is a fast-growing lymphoma. But it is treatable.
Burkitt lymphoma. This type makes up about 1% to 2% of all lymphomas. It is similar to Burkitt-like lymphoma. Close to 90% of people with this disease are boys or men. The average age is about 30. This lymphoma grows very quickly. But more than half are cured by aggressive chemotherapy.
Lymphoplasmacytic lymphoma or Waldenstrom macroglobulinemia. This is a rare type of lymphoma. It is found mainly in the bone marrow, lymph nodes, and spleen. People with this type usually live longer than 5 years. But their disease is usually not curable.
Hairy cell leukemia. Despite its name, this is often considered to be a type of lymphoma. Only about 700 people in the United States are diagnosed with this type every year. It's named for the hair-like look of its cells. This lymphoma is typically found in the bone marrow, spleen, and blood. It tends to be slow growing and is often curable.
Primary central nervous system (CNS) lymphoma. This type usually grows in the brain. It may also be found in the spinal cord and the tissues around it, as well as in the eye. Over time, it becomes widespread in the central nervous system. This type of lymphoma is more common in people with immune system problems, such as AIDS.
The common types of T-cell lymphoma include:
Angioimmunoblastic T-cell lymphoma. This type tends to occur in the lymph nodes, spleen, and liver. It causes infections, fever, weight loss, and skin rashes. It's not clear if this lymphoma is curable. Some people may need a stem cell transplant.
Extranodal natural killer/T-cell lymphoma, nasal type. This type often grows in the upper airway passages, such as the nose and upper throat. It can also grow into the skin and digestive tract. A person of any age can develop this type of lymphoma. If it's only in the nasal passages, it can often be cured by chemotherapy and radiotherapy. If it's widespread, cure is less likely.
Enteropathy-type T-cell lymphoma. This type occurs in people with sensitivity to gluten, the main protein in wheat flour. Celiac disease, or gluten-sensitive enteropathy, is a disease that can turn into this type of lymphoma. It often grows into the walls of the intestines. Once that occurs, recovery is not likely.
Subcutaneous panniculitis-like T-cell lymphoma. This rare lymphoma causes lumps to form in the deepest layers of the skin. It can be treated with radiation and sometimes chemotherapy.
Anaplastic large cell lymphoma. About 1% to 2% of lymphomas are this kind. It is a fast-growing type that often occurs in children. It starts in the lymph nodes and can also spread to the skin. Treatment with chemotherapy often works well.
Precursor T-lymphoblastic lymphoma/leukemia. This disease can be called lymphoma or leukemia. It depends on how much it's growing in the bone marrow. Leukemia grows more in bone marrow. About 1% of all lymphomas are this type. It often starts in the thymus, which is in the front part of the chest. People with this type are most often young men. The lymphoma is fast-growing. But the chance for a cure with chemotherapy is good if it hasn't spread to the bone marrow when first diagnosed.
Cutaneous T-cell lymphoma (mycosis fungoides, Sezary syndrome). This begins in the skin. It accounts for about 5% of all lymphomas. It begins as a patchy, red rash. It can grow into solid, raised tumors that can grow into lymph nodes and organs, such as the liver and spleen. With Sezary syndrome, the lymphoma cells are found in the blood. The prognosis is better if the lymphoma hasn't spread.
Peripheral T-cell lymphoma, unspecified. This term is used to describe T-cell lymphoma that doesn't fit in other categories. Most people with this type of lymphoma are in their 60s. It tends to grow quickly and be widespread.
Talking with your healthcare provider
If you have questions about non-Hodgkin lymphoma, talk with your healthcare provider. Your healthcare provider can help you understand more about this cancer.