The Children’s Mercy Leukemia and Lymphoma Program has compiled the following information for families who want to better understand the types, causes and treatments for lymphoma. You can also visit the Children’s Mercy Health Library or the Leukemia and Lymphoma Society for more information.
What is lymphoma?
Lymphoma is a cancer of the lymph nodes. Lymph nodes are part of the immune system and are located throughout the body.
Normal lymph nodes are usually less than 1 or 1.5 cm in size, depending on where they are located. In lymphoma, cells within the lymph nodes become malignant and cause the lymph node to grow in size. Often, when lymphoma is diagnosed in children and adolescents, it has spread to multiple lymph nodes.
Causes of lymphoma
Lymphoma is caused by genetic mutations that occur in a single cell that result in the loss of normal function and cause the cell to grow and divide very rapidly. In the majority of cases, these mutations occur randomly and are not inherited from family members. In most cases of childhood lymphoma, no cause can be found.
There are a few things that can place a child at increased risk for lymphoma. Defects in the immune system can place children at increased risk for several types of lymphoma. Immunosuppressive medications can also place children at risk for lymphoma, including those used after solid organ transplantation.
Symptoms of lymphoma
The most common symptom in lymphoma is one or more enlarged lymph nodes. These are typically not painful and are found most frequently in the neck, under the arm or in the groin, although they can be found anywhere.
Certain types of lymphoma can present with large masses in the chest or the abdomen. When this occurs, symptoms may be caused by pressure of the tumor on other organs and can include difficulty breathing, coughing, abdominal pain, vomiting and swelling. Children with lymphoma sometimes have other symptoms such as fever, fatigue, night sweats or weight loss.
Lymphoma is most often diagnosed from a lymph node biopsy. In most cases, the entire lymph node is removed and examined. Blood tests, bone marrow aspiration, and imaging tests may also be used to confirm the diagnosis.
Types of lymphoma
Hodgkin lymphoma makes up almost half of all childhood lymphomas and 6% of all children diagnosed with cancer. Hodgkin lymphoma is typically diagnosed in older children and adolescents.
The first sign of Hodgkin lymphoma is usually an enlarged, non-tender lymph node. The most frequent location is the neck, but lymph nodes can also be found under the arm, above the clavicle or in the groin.
In most cases of Hodgkin lymphoma, multiple lymph node sites are involved, including lymph nodes in the chest that can be seen using an X-ray. In some cases, patients with Hodgkin lymphoma can also have ‘B’ symptoms. These include fever, drenching night sweats and significant weight loss.
There are multiple pathologic subtypes of Hodgkin, including nodular sclerosing (most common), mixed cellularity, lymphocyte-rich, lymphocyte-depleted and nodular lymphocyte-predominant. Except for nodular lymphocyte-predominant, the other subtypes are collectively referred to as Classical Hodgkin lymphoma and treated in the same manner.
Nodular lymphocyte-predominant Hodgkin lymphoma is associated with an excellent outcome and low stage at diagnosis. Patients with this subtype of lymphoma can be cured with surgery alone, if the lymphoma is isolated to a single lymph node that can be removed.
Classical Hodgkin lymphoma is curable for most children and adolescents using chemotherapy and radiation therapy. In select cases, radiation therapy can be avoided if the lymphoma responds well to chemotherapy and there are no other high-risk features.
Despite very high cure rates, the treatment for Hodgkin lymphoma is associated with infrequent but important long-term effects. These include chronic heart or lung damage, loss of fertility and an increased risk of developing a second cancer related to treatment, including thyroid and breast cancer.
Non-Hodgkin Lymphoma (NHL)
NHL includes a number of different lymphomas with some similar characteristics. In total, NHL makes up slightly more than half of all childhood lymphoma, and 7% of all childhood cancer. In the United States, approximately 800 children are diagnosed with NHL each year. There are five main types of NHL that are seen in children.
Burkitts Lymphoma (BL): BL makes up about 40% of NHL in children. BL tends to be a very fast growing cancer and symptoms often develop very quickly. It can be present anywhere in the body at diagnosis including the central nervous system and the bone marrow. BL is very susceptible to most chemotherapy and cure rates exceed 90%.
Lymphoblastic Lymphoma (LL): LL makes up about 30% of NHL seen in children. When children are diagnosed with LL, they often have multiple large lymph nodes, an enlarged spleen and can have a large mass in the chest than can cause difficulty breathing. Treatment for LL is nearly identical to the treatment of acute lymphoblastic leukemia and cure rates are high at around 90%.
Diffuse Large B Cell Lymphoma (DLBCL): DLBCL makes up about 20% of NHL in children. It can present with enlarged lymph nodes anywhere throughout the body. DLBCL is similar to Burkitts lymphoma but tends to progress more slowly. Treatment is the same as for Burkitts with survival rates that exceed 90%.
Anaplastic Large Cell Lymphoma (ALCL): ALCL makes up about 10% of childhood NHL. Symptoms at diagnosis range from simply having an enlarged lymph node to a more widespread illness that can involve multiple lymph nodes, the soft tissue and the skin. ALCL rarely spreads to the central nervous system. Treatment includes chemotherapy only and cure rates are about 70%.
Primary Mediastinal B-Cell Lymphoma (PMBCL): PMBCL is a rare type of NHL diagnosed in children that typically presents with a large chest mass. Patients with PMBCL are treated with a unique chemotherapy regimen adopted from adult patients.