A lymphoma is a cancer of the lymphatic system, which is a part of the body's immune system and helps filter out bacteria, viruses, and other unwanted substances.
Most of the time, we're not aware of the inner workings of our lymphatic systems unless the lymph nodes, or glands, become swollen. This often happens during illness — a sign that the lymphatic system is working hard to filter harmful substances out of the body.
Non-Hodgkin lymphoma is a disease in which cancer cells form in the lymphatic system and start to grow uncontrollably.
There are several different types of lymphomas. Some involve lymphoid cells (called Reed-Sternberg cells) and are grouped under the heading of Hodgkin lymphoma.
All other forms of lymphoma fall into the non-Hodgkin grouping. The different forms of non-Hodgkin lymphoma are characterized by the malignant growth of white blood cells that live in the lymph nodes, called lymphocytes.
The exact cause of non-Hodgkin lymphoma is unclear, but doctors have identified some risk factors, such as:
Although no lifestyle factors have been definitively linked to childhood lymphomas, kids who have received either radiation treatments or chemotherapy for other types of cancer seem to have a higher risk of developing lymphoma later in life.
In most cases of patients with non-Hodgkin lymphoma, doctors are never able to determine a specific cause for the disorder. Not knowing the cause, however, doesn’t change the fact that experts are getting better and better at treating the problem.
Regular pediatric checkups may spot early symptoms of lymphoma in cases where this cancer is linked to the treatments or conditions mentioned above.
Symptoms of non-Hodgkin lymphoma vary depending on the type of lymphoma and where a tumor is located. Some kids might have stomach pain, constipation, and decreased appetite. Others may have trouble breathing, difficulty swallowing, coughing, wheezing, or chest pain.
Other symptoms can include:
Some kids' first symptom is swollen lymph nodes — usually in the neck, armpits, and groin. Of course, swollen lymph nodes do not usually mean cancer — they're most often a sign of a common illness, like an infection. In fact, all of the symptoms of non-Hodgkin lymphoma also can be caused by other conditions, which is why only a doctor can determine what's really wrong.
After performing a thorough evaluation, which includes a medical history and physical examination, a doctor who suspects non-Hodgkin lymphoma will refer the child to an oncologist, or cancer doctor.
The oncologist may perform a biopsy, or tissue sample, of lymph nodes. During a biopsy, a tiny bit of tissue is removed from the body and sent out to a laboratory for analysis. Depending on the type of biopsy ordered, the patient may be given local anesthesia (where only a part of the body is numbed) or general anesthesia (where the patient is asleep) to ensure there's no pain.
Biopsies used to test for non-Hodgkin lymphoma include:
Other tests used to diagnose non-Hodgkin lymphoma include:
Treatment of childhood lymphoma is largely determined by staging. Staging is a way to categorize or classify patients according to how extensive the disease is at the time of diagnosis.
The four stages of lymphoma range 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 doctors choose appropriate treatments and predict how someone with lymphoma will do in the long term.
The most common treatment for non-Hodgkin lymphoma is chemotherapy (medication that kills or stops the growth of cancer cells), though some patients will receive radiation therapy.
Kids who receive very aggressive treatments may undergo bone marrow or stem cell transplants to replace cells damaged by high doses of chemo or radiation. These transplants involve taking the cells from bone marrow or blood that has either been donated or taken from the patient and inserting them into the patient's bloodstream.
In a few special situations (such as high-risk patients or those whose cancer has come back), doctors will use immunotherapy (or biological therapy) to treat non-Hodgkin lymphoma. In immunotherapy, doctors use substances that occur naturally in the body to build up someone's natural resistance to disease. Although these substances occur naturally in the body, the ones used in this procedure are often manufactured in a laboratory.
Children treated with chemotherapy or radiation for non-Hodgkin lymphoma usually experience side effects. Most are temporary — although, as with all medical treatments, each child is unique and experiences side effects differently. The severity of side effects and how long they last depends on the individual and the medicines and treatments used.
The most common short-term side effects of chemo are nausea (although medications can treat this), vomiting, a lowering of blood counts resulting in an increased risk for infection or bleeding, or a flu-like feeling. Some kids feel weak or dizzy after their treatments, or run a fever. Others get sores in their mouths or suddenly don't feel much like eating. It's also common for kids to lose some or all of their hair.
The short-term side effects of radiation can be similar to those of chemotherapy, but usually are more localized, meaning they affect only the area that receives the radiation treatment. Kids can continue to feel side effects for weeks after their treatment ends.
Most kids with non-Hodgkin lymphoma are cured. Some with severe disease, however, will have a relapse (reoccurrence of the cancer) that doesn't respond to conventional treatments. For them, bone marrow transplants and stem cell transplants may be performed.