What is Lymphoma?
Lymphoma is a general term for malignancies of lymphocytes or, more rarely, of histiocytes. Collectively, these cell types form the reticuloendothelial system and circulate in the vessels of the lymphatic system. Traditionally, Lymphoma is classified as Hodgkin's disease, discovered by Thomas Hodgkin in 1832, and non-Hodgkin's lymphoma (all other types of lymphoma). Modern classifications of lymphoma have moved away from this artificial division.



What is Non-Hodgkin's lymphoma?
Non-Hodgkin's lymphoma is a type of cancer. Lymphoma is a general term for cancers that develop in the lymphatic system. Hodgkin's disease is one type of lymphoma. All other lymphomas are grouped together and are called non-Hodgkin's lymphoma. Lymphomas account for about 5 percent of all cases of cancer in the United States.

The lymphatic system is part of the body's immune system. It helps the body fight disease and infection. The lymphatic system includes a network of thin tubes that branch, like blood vessels, into tissues throughout the body. Lymphatic vessels carry lymph, a colorless, watery fluid that contains infection-fighting cells called lymphocytes. Along this network of vessels are small organs called lymph nodes. Clusters of lymph nodes are found in the underarms, groin, neck, chest, and abdomen. Other parts of the lymphatic system are the spleen, thymus, tonsils, and bone marrow. Lymphatic tissue is also found in other parts of the body, including the stomach, intestines, and skin.

Cancer is a group of many related diseases that begin in cells, the body's basic unit of life. To understand non-Hodgkin's lymphoma, it is helpful to know about normal cells and what happens when they become cancerous. The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes cells keep dividing when new cells are not needed, creating a mass of extra tissue. This mass is called a growth or tumor. Tumors can be either benign (not cancerous) or malignant (cancerous).

In non-Hodgkin's lymphoma, cells in the lymphatic system become abnormal. They divide and grow without any order or control, or old cells do not die as cells normally do. Because lymphatic tissue is present in many parts of the body, non-Hodgkin's lymphoma can start almost anywhere in the body. Non-Hodgkin's lymphoma may occur in a single lymph node, a group of lymph nodes, or in another organ. This type of cancer can spread to almost any part of the body, including the liver, bone marrow, and spleen.



What are the most common symptoms?
The most common symptom of non-Hodgkin's lymphoma is a painless swelling of the lymph nodes in the neck, underarm, or groin.

Other symptoms may include the following:

* Unexplained fever
* Night sweats
* Constant fatigue
* Unexplained weight loss
* Itchy skin
* Reddened patches on the skin

When symptoms like these occur, they are not sure signs of non-Hodgkin's lymphoma. They may also be caused by other, less serious conditions, such as the flu or other infections. Only a doctor can make a diagnosis. When symptoms are present, it is important to see a doctor so that any illness can be diagnosed and treated as early as possible. Do not wait to feel pain; early non-Hodgkin's lymphoma may not cause pain.



Types of Non-Hodgkin's Lymphoma
Over the years, doctors have used a variety of terms to classify the many different types of non-Hodgkin's lymphoma. Most often, they are grouped by how the cancer cells look under a microscope and how quickly they are likely to grow and spread. Aggressive lymphomas, also known as intermediate and high-grade lymphomas, tend to grow and spread quickly and cause severe symptoms. Indolent lymphomas, also referred to as low-grade lymphomas, tend to grow quite slowly and cause fewer symptoms. One of the paradoxes of non-Hodgkin's lymphoma is that the indolent lymphomas generally cannot be cured by chemotherapy, while in a significant number of cases aggressive lymphomas can be. Current lymphoma classification is complex. Common types of lymphomas include follicular lymphoma and diffuse large B cell lymphoma.



Diagnosis
If non-Hodgkin's lymphoma is suspected, the doctor asks about the person's medical history and performs a physical exam. The exam includes feeling to see if the lymph nodes in the neck, underarm, or groin are enlarged. In addition to checking general signs of health, the doctor may perform blood tests.

The doctor may also order tests that produce pictures of the inside of the body. These may include:

* X-rays: Pictures of areas inside the body created by high-energy radiation.
* CT scan (also known as a "CAT scan"): A series of detailed pictures of areas inside the body. The pictures are created by a computer linked to an x-ray machine.
* MRI (magnetic resonance imaging): Detailed pictures of areas inside the body produced with a powerful magnet linked to a computer.
* Lymphangiogram: Pictures of the lymphatic system taken with x-rays after a special dye is injected to outline the lymph nodes and vessels.

A biopsy is needed to make a diagnosis. A surgeon removes a sample of tissue so that a pathologist can examine it under a microscope to check for cancer cells. A biopsy for non-Hodgkin's lymphoma is usually taken from a lymph node, but other tissues may be sampled as well. Sometimes, an operation called a laparotomy may be performed. During this operation, a surgeon cuts into the abdomen and removes samples of tissue to be checked under a microscope.

A patient who needs a biopsy may want to ask the doctor some of the following questions:

* Why do I need to have a biopsy?
* How long will the biopsy take? Will it hurt?
* How soon will I know the results?
* If I do have cancer, who will talk with me about treatment? When?



Staging
If non-Hodgkin's lymphoma is diagnosed, the doctor needs to learn the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, what parts of the body are affected. Treatment decisions depend on these findings.

The doctor considers the following to determine the stage of non-Hodgkin's lymphoma:

* The number and location of affected lymph nodes;
* Whether the affected lymph nodes are above, below, or on both sides of the diaphragm (the thin muscle under the lungs and heart that separates the chest from the abdomen); and
* Whether the disease has spread to the bone marrow, spleen, or to organs outside the lymphatic system, such as the liver.

In staging, the doctor may use some of the same tests used for the diagnosis of non-Hodgkin's lymphoma. Other staging procedures may include additional biopsies of lymph nodes, the liver, bone marrow, or other tissue. A bone marrow biopsy involves removing a sample of bone marrow through a needle inserted into the hip or another large bone. A pathologist examines the sample under a microscope to check for cancer cells.



Stages of NHL
The various stages of NHL (the Ann Arbor staging classification, developed for Hodgkin's lymphoma) are based on how far the cancer has spread throughout and beyond the lymphatic system, and whether constitutional symptoms (fever, night sweats, or weight loss) are present.

"Stage I" indicates that the cancer is located in a single region, usually one lymph node and the surrounding area. Stage I often will not have outward symptoms.

"Stage II" indicates that the cancer is located in two separate regions, an affected lymph node or organ within the lymphatic system and a second affected area, and that both affected areas are confined to one side of the diaphagm - that is, both are above the diaphragm, or both are below the diaphragm.

"Stage III" indicates that the cancer has spread to both sides of the diaphragm, including one organ or area near the lymph nodes or the spleen.

"Stage IV" indicates that the cancer has spread beyond the lymphatic system and involves one or more major organs, possibly including the bone marrow or skin.

The absence of constitutional symptoms is denoted by adding an "A" to the stage; the presence is denoted by adding a "B" to the stage.

Staging in Non-Hodkin's lymphomas is far less significant in determining therapy than it is in Hodgkin's lymphoma.



Treatment
The doctor develops a treatment plan to fit each patient's needs. Treatment for non-Hodgkin's lymphoma depends on the stage of the disease, the type of cells involved, whether they are indolent or aggressive, and the age and general health of the patient.

Non-Hodgkin's lymphoma is often treated by a team of specialists that may include a hematologist, medical oncologist, and/or radiation oncologist. Non-Hodgkin's lymphoma is usually treated with chemotherapy, radiation therapy, or a combination of these treatments. In some cases, bone marrow transplantation, biological therapies, or surgery may be options. For indolent lymphomas, the doctor may decide to wait until the disease causes symptoms before starting treatment. Often, this approach is called "watchful waiting."

Taking part in a clinical trial (research study) to evaluate promising new ways to treat non-Hodgkin's lymphoma is an important option for many people with this disease.