A lymphoma is a cancer of the lymphatic system. The lymphatic system 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.
About Non-Hodgkin Lymphoma
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 Hodgkin disease or 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:
- having conditions that weaken the immune system, like AIDS (acquired immunodeficiency syndrome)
- taking immune-suppressing medications after organ transplants
- exposure to certain viruses, such as Epstein-Barr virus (the virus that usually causes mono)
- having a sibling with the disease
- being white and male
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.
Regular pediatric checkups may spot early symptoms of lymphoma in cases where this cancer is linked to the treatments or conditions mentioned above.
Signs and Symptoms
Symptoms of non-Hodgkin lymphoma vary depending on the type of lymphoma and where a tumor is located. Some kids may feel stomach pain, constipation, and decreased appetite. Others may have trouble breathing, difficulty swallowing, coughing, wheezing, or chest pain.
Other symptoms may include:
- painless swollen lymph nodes
- fever, chills, or night sweats
- itchy skin
- weight loss despite eating normally
- bone or joint pain
- recurring infections
The symptom that some kids first experience 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 can also be caused by other conditions, which is why only a doctor can determine what's really wrong with a child.
After performing a thorough evaluation, which includes a medical history and physical examination, a doctor who suspects that a child has non-Hodgkin lymphoma will refer the child to an oncologist, or cancer doctor.
The doctor 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 doctor may use local anesthesia (where only a part of the body is numbed) or general anesthesia (which puts a child to sleep) to ensure that the child doesn't feel any pain.
Biopsies used to test for non-Hodgkin lymphoma include excisional biopsy (where the doctor opens the skin to remove an entire lymph node) or incisional biopsy (where the doctor removes only a part of the lymph node).
Another type of biopsy, fine needle aspiration (where a doctor uses a very thin needle to suction out a small amount of tissue from the lymph node), is used on some rare occasions to diagnose non-Hodgkin lymphoma.
Doctors also may perform a bone marrow biopsy, where a needle is used to take samples of the soft tissue found inside a bone.
Other tests used to diagnose non-Hodgkin lymphoma include:
- blood tests
- a chest X-ray, a simple procedure in which the person lies on a table while an X-ray machine takes an image of the chest
- a computerized tomography (CT or CAT) scan, which rotates around the patient and creates an X-ray picture of the inside of the body from different angles
- an ultrasound, which uses high-frequency sound waves to create pictures of the inside of the body
- a magnetic resonance imaging (or MRI) scan, which uses magnets and radio waves to allow doctors to see inside the body.
- a gallium scan, which uses the injection of a material known as gallium to help show tumors and inflammation
- a bone scan to detect bone changes
- a positron emission tomography (PET) scan, which can tell the difference between normal and abnormal cells based on metabolic activity
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.
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 guide medical professionals regarding therapy and help them predict how someone with lymphoma will do in the long term.
The most common treatment for non-Hodgkin lymphoma is chemotherapy. Chemotherapy kills or stops the growth of cancer cells. Patients are also sometimes treated with radiation therapy. In addition, some people may have surgery to remove tumors.
For children who are receiving very aggressive chemotherapy or radiation treatments, doctors may perform bone marrow or stem cell transplants to replace cells damaged by the chemotherapy or radiation. These transplants involve taking the cells from bone marrow or blood that has either been taken from the patient or donated by another person. These cells are then inserted into the patient's bloodstream to replace those that have been damaged or destroyed.
In a few special situations (such as high-risk patients or patients whose cancer has come back), doctors are using a new type of therapy called immunotherapy (or biological therapy) to treat older kids with 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 type of medicine and treatment that the doctor prescribes.
The most common short-term side effects of chemotherapy are nausea, vomiting, 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.
When total-body irradiation is used prior to bone marrow transplant, there is an increased risk that the child will have slowed growth, thyroid problems, abnormal function of the ovaries or testicles, or cataracts.
The majority of kids with non-Hodgkin lymphoma are cured, meaning they will have cancer-free survival for more than 5 years. Five-year survival is about 90% for those with Stage I or Stage II at the time of diagnosis, and close to 70% for those with more advanced Stage III or IV disease.
Although most kids do recover from lymphoma, some with severe disease 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 to remove residual cancer cells. Healthy cells are introduced into the body in the hopes that it will begin producing white blood cells that will help the child fight infections.
Promising new treatments are being developed for childhood lymphomas, including several different types of immunotherapy, specifically the use of antibodies to deliver chemotherapy medicines or radioactive chemicals directly to lymphoma cells. This direct targeting of lymphoma cells may prevent the toxic side effects that occur when today's chemotherapy and radiation treatments damage normal, noncancerous body tissues.
Reviewed by: Donna Patton, MD
Date reviewed: April 2009