Non-Hodgkin's lymphoma (NHL)

What is non-Hodgkin's lymphoma (NHL)?

Non-Hodgkin's lymphoma is cancer in the lymphatic system. Sixty percent of lymphomas are non-Hodgkin's lymphomas. The lymphatic system is part of the immune system and functions to fight disease and infections.

The lymphatic system includes:

• Lymph fluid - fluid containing lymphocyte cells.
• Lymph vessels - thin tubes that carry lymph fluid throughout the body.
• Lymphocytes - specific white blood cells that fight infections and disease.
• Lymph nodes - bean-shaped organs, found in the underarm, groin, neck, chest and abdomen, that act as filters for the lymph fluid as it circulates through the body.

Non-Hodgkin's lymphoma causes the cells in the lymphatic system to abnormally reproduce, eventually causing tumors to grow. Non-Hodgkin's disease cells can also spread to other organs and tissues in the body.

Non-Hodgkin's lymphoma is the third most common childhood cancer. It occurs most often in children between the ages of 7 and 11, but can occur at any age from infancy to adulthood.

Non-Hodgkin's lymphoma affects males almost three times more often than females, and is more common among Caucasian children than among African-American children and children of other races.

Staging and classification of non-Hodgkin's lymphoma is based on the extent of the disease and the specific cells involved.

What are the different types of non-Hodgkin's lymphoma?

There are three subtypes of non-Hodgkin's lymphoma, including the following:

• Lymphoblastic non-Hodgkin's lymphoma - Lymphoblastic non-Hodgkin's lymphoma accounts for about 35 percent of the cases, involves the T-cells, and usually presents with a mass in the chest, swollen lymph node(s), with or without bone marrow and central nervous system involvement.
• Burkitt's or non-Burkitt's lymphoma - Burkitt's or non-Burkitt's lymphoma is a non-Hodgkin's disease in which the cells are undifferentiated and diffuse. This has also been referred to as small non-cleaved cells. Burkitt's and non-Burkitt's lymphoma accounts for about 40 to 50 percent of the cases and is usually characterized by a large abdominal tumor and may have bone marrow and central nervous system involvement.
• Large cell or diffuse histiocytic non-Hodgkin's lymphoma - Large cell or diffuse histiocytic non-Hodgkin's involves the B-cells and T-cells and accounts for about 15 to 20 percent of the cases. Children with this type of non-Hodgkin's lymphoma usually have lymphatic system involvement, as well as a non-lymph structure (i.e., lung, jaw, brain, skin and bone) involvement.

How is non-Hodgkin's lymphoma staged?

Staging is the process of determining whether cancer has spread and, if so, how far. There are various staging symptoms that are used for non-Hodgkin's lymphoma. Always consult your child's physician for information on staging. One method of staging non-Hodgkin's lymphoma is the following:

• Stage I - involves the tumor at one site, either nodal or elsewhere in the body.
• Stage II - involves the tumor at two or more sites on the same side of the body.
• Stage III - involves tumors in any number that occur on both sides of the body, but does not involve bone marrow or the central nervous system.
• Stage IV - is any stage of tumor that also has bone marrow and/or central nervous system involvement. Stage IV is also subdivided depending on the amount of blasts (cancer cells) present in the bone marrow.

What causes non-Hodgkin's lymphoma?

The specific cause of non-Hodgkin's lymphoma is unclear. It is possible that genetics and exposure to viral infections may increase the risk for developing this malignancy. Non-Hodgkin's lymphoma has also been linked to chemotherapy and radiation therapy. Non-Hodgkin's may be a second malignancy as a result of the treatment for certain cancers.

There has been much investigation into the association of the Epstein-Barr virus (EBV) that causes the mononucleosis infection; as well as the human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). Both of these infectious viruses have been linked to the development of Burkitt's lymphoma.

The majority of Burkitt's lymphoma cases result from a chromosome rearrangement between chromosome #8 and #14, which causes genes to change positions and function differently, promoting uncontrolled cell growth. Other chromosome rearrangements have been seen in non-Hodgkin's lymphoma (all types) that are also thought to promote excessive cell growth.

Children and adults with other hereditary abnormalities have an increased risk of developing non-Hodgkin's lymphoma, including patients with ataxia telangiectasia, X-linked lymphoproliferative disease or the Wiskott-Aldrich syndrome.

What are the symptoms of non-Hodgkin's lymphoma?

Most children have stage III or IV disease at the time of diagnosis because of the sudden onset of symptoms. The disease can progress quickly from a few days to a few weeks. A child can go from otherwise healthy to having multi-system involvement in a short time period.

Some children with non-Hodgkin's lymphoma have symptoms of an abdominal mass and have complaints of abdominal pain, fever, constipation and decreased appetite - due to the pressure and obstruction a large tumor in this area can cause.

Some children with non-Hodgkin's lymphoma have symptoms of a mass in their chest and have complaints of respiratory problems, pain with deep breaths (dyspnea), cough or wheezing.

Because of the rapid onset of this malignancy, any respiratory symptoms can quickly worsen, causing a life-threatening emergency.

The following are the most common symptoms of non-Hodgkin's lymphoma. However, each child may experience the symptoms differently. Symptoms may include:

• Painless swelling of the lymph nodes in neck, chest, abdomen, underarm or groin.
• Fever.
• Sore throat.
• Fullness in groin area from node involvement.
• Bone and joint pain.
• Night sweats.
• Tiring easily (fatigue).
• Weight loss/decreased appetite.
• Itching of the skin.
• Recurring infections.

The symptoms of non-Hodgkin's lymphoma may resemble other blood disorders or medical problems. Always consult your child's physician for a diagnosis.

How is non-Hodgkin's lymphoma diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for non-Hodgkin's lymphoma may include:

• Blood and urine tests.
• X-rays of the chest - use invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
• Computed tomography scan of the abdomen, chest and pelvis (Also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat and organs. CT scans are more detailed than general x-rays.
• Lymph node biopsy - a sample of tissue is removed from the lymph node and examined under a microscope.
• Lymphangiogram - an imaging study that can detect cancer cells or abnormalities in the lymphatic system and structures. It involves a dye being injected into the lymph system.
• Bone marrow aspiration/biopsy (to detect cancer cells) - a procedure that involves a small amount of bone marrow fluid and tissue to be taken, usually from part of the hip bones, to further examine the number, size, and maturity of blood cells and/or abnormal cells.
• Lumbar puncture (to evaluate central nervous system disease for cancer cells) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing. CSF is the fluid which bathes the brain and spinal cord.

Treatment of non-Hodgkin's lymphoma:

Specific treatment for non-Hodgkin's lymphoma will be determined by your child's physician based on:

• Your child's age, overall health and medical history.
• The extent of the disease.
• Your child's tolerance for specific medications, procedures or therapies.
• The expectations for the course of the disease.
• Your opinion or preference.

Treatment may include (alone or in combination):

• Chemotherapy.
• Radiation therapy.
• Surgery.
• Close monitoring of blood work.
• Bone marrow transplant.
• Bone marrow examinations.
• Lumbar punctures/spinal taps.
• Antibiotics (to prevent or treat infections).
• Long-term follow up care (to determine response to treatment, detect recurrent disease and manage late effects of treatment).

Long-term outlook for a child with non-Hodgkin's lymphoma:

Prognosis greatly depends on:

• The extent of the disease.
• The presence or absence of metastasis.
• The response to therapy.
• Age and overall health of the child.
• Your child's tolerance of specific medications, procedures or therapies.
• New developments in treatment.

As with any cancer, prognosis and long-term survival can vary greatly from child to child. Every child is unique and treatment and prognosis is structured around the child. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for the child diagnosed with non-Hodgkin's lymphoma. Side effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of non-Hodgkin's lymphoma. New methods are continually being discovered to improve treatment and to decrease side effects.