Lymphoma is cancer of the lymphatic system, which includes the following disease-fighting organs:
Lymph tissue is also found in many other parts of the body, including the tonsils and digestive system.
Lymphoma starts when a white blood cell called a lymphocyte is damaged and begins to reproduce rapidly. These new “lymphoma” cells are flawed like the parent cell and don’t help the body fight infection. Eventually lymphoma cells crowd out healthy lymphocytes and form tumors in the organs of the lymphatic system. In the advanced stages of the disease, these tumors can metastasize (spread) beyond the lymphatic system.
Lymphoma usually (but not always) begins in the lymph nodes. There are about 600 lymph nodes scattered throughout the human body. Their function is to store white blood cells and to trap and destroy bacteria and other harmful substances. In addition, lymphoma can start in the lungs, stomach, intestines, brain, bones and skin.
There are two main types of lymphoma. Each has many subtypes.
Hodgkin lymphoma usually affects young adults and people over 55. About 10 to 15 percent of cases are in children and teens. In 2014, about 9,000 people will be diagnosed with Hodgkin lymphoma, and 1,000 will die from the disease.
Non-Hodgkin lymphoma is one of the most common cancers in the United States, accounting for about four percent of all cancers. About 70,000 people are diagnosed with NHL every year, and about 20,000 die annually from the disease. The lifetime risk of developing NHL is about 1 in 50. Ninety-five percent of people with NHL are adults, and half of all patients are over 65.
All cancers, including lymphoma, begin when a cell’s genetic information is damaged.
Every cell in the body has a genetic “blueprint” located in its nucleus. This information is encoded in a series of proteins called DNA. Every time the cell divides, its DNA replicates (copies itself). If something goes wrong during this process, it can cause permanent changes to the DNA. Substances in the environment can also damage DNA. In some (but not all) cases, cells with damaged DNA become cancer cells.
No one knows exactly what causes the genetic damage that leads to lymphoma. Some possible risk factors for the disease include:
Many people with lymphoma have no known risk factors.
The most common symptom of lymphoma is an enlarged lymph node, which usually appears in the neck, groin, armpit or above the collarbone. Infections like colds or flu can also cause lymph nodes to puff up temporarily, but see a doctor if the swelling persists for two weeks or more.
Other possible lymphoma symptoms include:
If you have symptoms of lymphoma, your doctor may refer you to an oncologist (cancer specialist) or hematologist (blood disorders specialist).
Diagnosis of lymphoma begins with a history and physical exam. The physician palpates (feels) the organs and lymph nodes for swellings and abnormalities.
If lymphoma is suspected, the doctor will order a biopsy (surgical removal) of lymph node tissue. This is sent to lab for microscopic examination and other diagnostic tests.
When a diagnosis of lymphoma is confirmed, the doctor will usually order additional tests to see how far the disease has spread:
Based on the results, the doctor will “stage” the lymphoma to describe how far it has spread. Stage I lymphoma is confined to a single organ or group of lymph nodes, while stage IV lymphoma has spread throughout the body to multiple organs.
Lymphoma treatment varies by disease type, stage and the patient’s preferences and overall health. The first goal of treatment is to destroy all lymphoma cells and achieve full remission. If this isn’t possible, the disease can sometimes be maintained in “partial” remission, meaning cancer cells are present, but the disease isn’t progressing.
Many lymphoma treatments have side effects such as nausea and decreased immune function. During treatment, it’s important to work closely with your medical team to monitor your overall health. Your doctor may prescribe additional medication and treatment (called palliative treatment) to help lessen side effects.
Treatment for lymphoma may involve one or several of the following:
Prognosis for lymphoma depends on many factors. It is generally best for early-stage lymphoma that is contained to a single organ or group of lymph nodes. However, unlike other types of cancer, stage III and IV lymphoma may be quite curable depending on the subtype present.
About 60 percent of NHL cases involve aggressive forms of the disease that spread quickly if left untreated. (However, aggressive lymphomas are often easier to cure completely than slower-growing types, which tend to recur over time.)
Because no one is sure what causes it, there is really no practical way to prevent lymphoma. Maintaining good overall health, adhering to a nutritious diet, practicing safe sex (to prevent sexually transmitted infections) and seeking prompt treatment for health problems may decrease your risk.