Hodgkin lymphoma is a type of cancer that affects the lymphatic system. This highly sophisticated filtering system helps the body's immune system remove bacteria, viruses, and other unwanted substances.

The lymphatic system includes the lymph nodes (glands), thymus, spleen, tonsils, adenoids, and bone marrow, as well as the channels (called lymphatics or lymph vessels) that connect them. When lymphoma occurs, cancer cells develop in a person's lymphatic system and start to grow uncontrollably.

The different types of lymphomas are grouped into two broad categories: Hodgkin lymphoma and non-Hodgkin lymphoma. Lymphomas that involve a type of cell known as a Reed-Sternberg cell are classified as Hodgkin lymphoma. The different subtypes of Hodgkin lymphoma are classified based on how the cancerous tissue looks under a microscope.

Lymphomas without Reed-Sternberg cells are usually classified as non-Hodgkin lymphomas.

Risk Factors

Hodgkin lymphoma tends to occur more often in teens and in people with severe immune deficiencies from things such as inherited immune defects, human immunodeficiency virus (HIV) infection, or treatment with immunosuppressive drugs after organ transplants. People over age 50 also can get Hodgkin lymphoma more often.

Usually, the causes of lymphoma are unknown and no lifestyle factors have been definitely linked to childhood lymphomas.

So, neither parents nor kids have control over the factors that cause the disease. Most lymphomas come from noninherited mutations (errors) in the genes of growing blood cells. Regular pediatric checkups can sometimes spot early symptoms of lymphoma.

Signs and Symptoms

The most common first symptom of Hodgkin lymphoma is a painless enlargement of the lymph nodes (often called "swollen glands") in the neck, the underarm area, or the groin.

If cancer involves the lymph nodes in the chest, pressure may trigger an unexplained cough, shortness of breath, or problems in blood flow to and from the heart.

About a third of patients have other nonspecific symptoms, including fatigue, poor appetite, itching, or rash. Unexplained fever, night sweats, and weight loss are also common.

Diagnosis

One of the things doctors might look for if they suspect lymphoma is enlargement of the lymph nodes. They may first try to treat swollen lymph nodes with antibiotics, because infections are the most common cause of swollen lymph nodes.

But if the lymph nodes remain swollen, a child may be referred to an oncologist (cancer doctor), who might recommend imaging studies and a biopsy (tissue sample) of the lymph nodes.

During a biopsy, a tiny bit of tissue is removed from the body and sent out to a laboratory for analysis. If Hodgkin lymphoma is suspected, one of these biopsies may be done:

• Core biopsy: the doctor uses a hollow needle to remove a small amount of tissue from the lymph node.
• Excisional or incisional biopsy: the doctor opens the skin to remove the entire enlarged lymph node (excisional) or only part of it (incisional).

Depending on the type of biopsy ordered, the doctor might use local anesthesia (where only a part of the body is numbed) or, most commonly, general anesthesia (in which a patient is asleep) to ensure there is no pain.

If the doctor suspects Hodgkin lymphoma, more tests will be done to determine if the cancer has spread. These can include:

• blood tests
• a chest X-ray
• a computed tomography (CT or CAT) scan, a type of X-ray that rotates around the patient and creates a picture of the inside of the body from different angles
• a bone marrow biopsy to check for cancer in the bone marrow
• a positron emission tomography (PET) scan, which can tell the difference between normal and abnormal cells based on their metabolic activity

Treatment

Treatment for Hodgkin lymphoma is very effective for most kids. The choice of treatment is largely determined by staging, a way to categorize or classify patients according to how extensive the disease is at the time of diagnosis.

There are four stages of lymphoma, ranging from Stage I (cancer involving only one area of lymph nodes or only one organ outside the lymph nodes) to Stage IV (cancer has spread, or metastasized, to one or more tissues or organs outside the lymphatic system). The stage at diagnosis can help medical professionals choose the appropriate therapy and predict how someone with lymphoma will do in the long term.

Treatment may involve radiation (the use of high-energy rays to shrink tumors and keep cancer cells from growing), chemotherapy (the use of highly potent medical drugs to kill cancer cells), or both, depending on the type and stage of the cancer as well as the age and overall health of the child.

For children whose cancer comes back after treatment or who do not respond well to treatment, doctors may perform bone marrow or stem cell transplants to replace cells damaged by chemotherapy or radiation. These transplants involve taking the cells from bone marrow or blood (either taken from the patient or donated by another person) and transplanting them to the patient after chemotherapy treatment.

Short-Term and Long-Term Side Effects

Treatment for Hodgkin lymphoma is powerful. It destroys good cells along with bad, which can create certain side effects.

Intensive lymphoma treatment affects the bone marrow, causing anemia and easy bleeding, and increasing the risk for serious infections. Chemotherapy treatments have side effects — some short-term (such as hair loss, increased infection risk, and nausea and vomiting) and some long-term (such as heart, thyroid, and kidney damage, reproductive problems, or the development of another cancer later in life) — that parents should discuss with the doctor.

Prognosis

The majority of kids with Hodgkin lymphoma are cured, meaning they will have long-term cancer-free survival. However, those with higher-stage disease are at risk for more long-term side effects as a result of more intensive treatment.

Reviewed by: Robin E. Miller, MD
Date reviewed: March 2012