(Hodgkin's Lymphoma; Hodgkin's Disease)
Hodgkin lymphoma is a type of lymphoma distinguished by the presence of a particular kind of cancer cell called a Reed-Sternberg cell.
The cause is unknown.
Lymph nodes enlarge but are not painful.
Other symptoms, such as fever and shortness of breath, develop depending on where the cancer cells are growing.
A lymph node biopsy is needed for diagnosis.
Chemotherapy and radiation therapy are used for treatment.
Most people are cured.
In the United States, about 9,000 new cases of Hodgkin lymphoma occur every year. The disease is more common in males than in females—about three men are affected for every two women. Hodgkin lymphoma rarely occurs before age 10. It is most common in people between the ages of 15 and 40 and in people older than 50.
The cause of Hodgkin lymphoma is unknown. Although there are some families in which more than one person has Hodgkin lymphoma, it is not contagious.
People with Hodgkin lymphoma usually become aware of one or more enlarged lymph nodes, most often in the neck but sometimes in the armpit or groin. Although usually painless, sometimes the enlarged lymph nodes may be painful for a few hours after a person drinks alcoholic beverages.
People with Hodgkin lymphoma sometimes experience fever, night sweats, and weight loss. They can also have itching and fatigue. Some people have Pel-Ebstein fever, an unusual pattern of high temperature for several days alternating with normal or below-normal temperature for days or weeks. Other symptoms may develop, depending on where the cancerous cells are growing. For example, enlargement of lymph nodes in the chest may partially narrow and irritate airways, resulting in a cough, chest discomfort, or shortness of breath. Enlargement of the spleen or lymph nodes in the abdomen may cause discomfort in the abdomen.
Symptoms of Hodgkin Lymphoma
Doctors suspect Hodgkin lymphoma when a person with no apparent infection develops persistent and painless enlargement of lymph nodes that lasts for several weeks. The suspicion is stronger when lymph node enlargement is accompanied by fever, night sweats, and weight loss. Rapid and painful enlargement of lymph nodes—which may occur when a person has a cold or infection—is not typical of Hodgkin lymphoma. Sometimes enlarged lymph nodes deep within the chest or abdomen are found unexpectedly when a chest x-ray or computed tomography (CT) is done for another reason.
Abnormalities in blood cell counts and other blood tests may provide supportive evidence. However, to make the diagnosis, doctors must do a biopsy of an affected lymph node to see if it is abnormal and if Reed-Sternberg cells are present. Reed-Sternberg cells are large cancerous cells that have more than one nucleus (a structure inside a cell that holds the cell's genetic material). Their distinctive appearance can be seen when a biopsy specimen of lymph node tissue is examined under a microscope.
The type of biopsy depends on which node is enlarged and how much tissue is needed. Doctors must remove enough tissue to be able to distinguish Hodgkin lymphoma from other disorders that can cause lymph node enlargement, including non-Hodgkin lymphomas, infections, or other cancers.
The best way to obtain enough tissue is with an excisional biopsy ( a small incision made to remove a piece of the lymph node). Occasionally, when an enlarged lymph node is close to the body's surface, a sufficient amount of tissue can be obtained by inserting a hollow needle through the skin and into the lymph node (needle biopsy). When an enlarged lymph node is deep inside the abdomen or chest, surgery may be needed to obtain a piece of tissue.
Before treatment is started, doctors must determine how extensively the lymphoma has spread—the stage of the disease. The choice of treatment and the prognosis are based on the stage. An initial examination may detect only a single enlarged lymph node, but procedures to find if and where the lymphoma has spread (staging) may detect considerably more disease.
The disease is classified into four stages based on the extent of its spread (I, II, III, IV). The higher the number, the more the lymphoma has spread. The four stages are subdivided, based on the absence (A) or presence (B) of one or more of the following symptoms:
For example, a person with a stage II lymphoma who has experienced night sweats is said to have stage IIB Hodgkin lymphoma.
Several procedures are used to stage or assess Hodgkin lymphoma. Basic blood tests, including tests of liver and kidney function, tests for human immunodeficiency virus (HIV) and hepatitis B and C infection, and chest x-rays and computed tomography (CT) of the chest, abdomen, and pelvis are standard. CT is quite accurate in detecting enlarged lymph nodes or spread of the lymphoma to the liver and other organs.
Positron emission tomography (PET) is the most sensitive technique for determining the stage of Hodgkin lymphoma and for evaluating the person's response to treatment. Because living tissue can be identified with PET, doctors can use this imaging technique to distinguish scar tissue from active Hodgkin lymphoma after the person has undergone treatment (although PET is not always accurate because inflammation can appear on PET). Most people with Hodgkin lymphoma do not need surgery to determine whether the disorder has spread to the abdomen, because all people receive chemotherapy, which treats the lymphoma no matter where it is located.
Stages of Hodgkin Lymphoma
With chemotherapy, with or without radiation therapy, most people who have Hodgkin lymphoma can be cured.
Chemotherapy is used for all stages of disease. Doctors usually use more than one chemotherapy drug. Several combinations may be used. Involved field radiation therapy (radiation therapy delivered only to the affected areas of the body, avoiding exposing unaffected areas to radiation) may be added after chemotherapy. Radiation therapy is usually given on an outpatient basis over about 3 to 4 weeks.
More than 80% of people with stage I or stage II disease are cured with chemotherapy alone or with chemotherapy plus involved field radiation therapy. The cure rate of people with stage III disease ranges from 70 to 80%. Cure rates for people with stage IV disease, while not as high, are above 50%.
Although chemotherapy greatly improves the chances for a cure, side effects can be serious. The drugs may cause temporary or permanent infertility, an increased risk of infection, potential damage to other organs, such as the heart or lungs, and reversible hair loss. After radiation therapy, there is an increased risk of cancer, such as lung, breast, or stomach cancer, occurring 10 or more years after treatment in organs that were in the radiation field. Non-Hodgkin lymphomas may develop in some people many years after successful treatment for Hodgkin lymphoma, regardless of the treatment used.
A person who has a remission (the disease under control) after initial treatment but then relapses (lymphoma cells reappear) may still be cured with second-line treatment. The cure rate for people who relapse is at least 50%. Among people who relapse in the first 12 months after initial treatment, cure rates are somewhat lower, whereas the rates for people who relapse later tend to be somewhat higher. People who relapse after initial treatment generally are treated with a “salvage” chemotherapy regimen followed by high-dose chemotherapy and autologous stem cell transplantation. Autologous stem cell transplantation, which involves using the person's own stem cells (see Stem Cell Transplantation), may be done after high-dose chemotherapy. High-dose chemotherapy with stem cell transplantation is generally a safe procedure, with less than a 1 to 2% risk of death related to the treatment.
After treatment has been finished, people have regular doctor's examinations and tests to look for return of the lymphoma (posttreatment surveillance). Tests typically include chest x-rays and CT scans of the chest and pelvis. If people have had radiation therapy, doctors also do tests, such as mammography or magnetic resonance imaging (MRI) of the breasts and thyroid tests to see if a new cancer developed in those organs.