Cancers of the lymphatic system — the third most common form of childhood cancer — are much more treatable today than in years past, thanks to advances in care. Miami Cancer Institute, Florida’s only member of the Memorial Sloan Kettering Alliance, is up-to-the-minute on these advances and can give our child and family comprehensive care and support from diagnosis through treatment and beyond.
What are lymphomas?
Lymphomas affect the lymphatic system, a network of glands and vessels that transports lymph, a clear fluid that contains infection-fighting white blood cells, including lymphocytes. Lymphocytes develop from young cells called stem cells. Lymphocytes circulate throughout the body and are concentrated in areas of the lymph system, such as the bone marrow, spleen, tonsils, thymus and lymph nodes (small bean-shaped organs found in the neck, chest, abdomen, groin and underarms).
When lymphocytes begin to grow and multiply uncontrollably, they can cause lymph nodes to enlarge. Lymphoma can spread to any other area of the body, including the bone marrow and the central nervous system.
What are the types of pediatric lymphoma?
Lymphoma is generally classified as either Hodgkin lymphoma or non-Hodgkin lymphoma, and each of these types has several subtypes.
Hodgkin lymphoma, also known as Hodgkin’s disease, most commonly affects children aged 15 and older. Children with Hodgkin lymphoma usually have abnormal cells called Reed-Sternberg cells in the cancerous lymph node. These cells may develop from a type of lymphocytes known as B cells.
The more common subtypes of Hodgkin lymphoma in children and young adults include:
- Nodular sclerosis (NS): In NS, Lymph nodes contain scar tissue (sclerosis), normal and abnormal lymphocytes and Reed-Sternberg cells. It is the most common subtype, affecting about 70 percent of children who have Hodgkin lymphoma.
- Mixed cellularity (MC): In MC, lymph nodes contain inflammatory immune cells and Reed-Sternberg cells. This form is most common in children younger than 10.
- Lymphocyte predominance (LP): In LP, abnormal lymphocytes and Reed-Sternberg cells are concentrated in the cancerous lymph node. This form is more common in younger children.
Non-Hodgkin lymphoma is more common in boys than girls. It is usually aggressive and grows quickly. The two main subtypes in children are:
- Highly aggressive (high-grade) tumors, including Burkitt lymphoma, non-Burkitt lymphoma and lymphoblastic lymphoma
- Intermediate-grade tumors, including follicular large-cell lymphoma, diffuse small cleaved cell lymphoma, mantle cell lymphoma, peripheral T cell lymphoma, immunoblastic diffuse large cell lymphoma, and anaplastic Ki-1 large-cell lymphoma (CD30+). These types of tumors are more common in adults, though they are sometimes seen in children.
What are the risk factors for pediatric leukemia?
Environmental risk factors are not thought to play a large role in childhood leukemia. Some risk factors include having a brother or sister with leukemia, certain genetic disorders, and having been treated with radiation or chemotherapy for another disease.
What can you do to prevent pediatric leukemia?
Because the known risk factors are not preventable, there are no recommended preventive measures.
What are the risk factors for lymphoma in children?
Many children with lymphoma have no recognized risk factors. Some risk factors for childhood lymphoma include:
- Gender: Hodgkin's lymphoma is more predominant in males than females.
- Race: Whites are more likely to contract the disease than other groups.
- Infections such as Epstein-Barr virus, which causes mononucleosis, and HIV, the virus that causes AIDS.
- Diseases of the lymphatic system, including lupus and rheumatoid arthritis.
- Immune deficiency syndromes, including:
- Bloom syndrome
- Common variable immunodeficiency
- Severe combined immunodeficiency syndrome (SCID)
- Wiskott-Aldrich syndrome
- Taking immunosuppressants after organ transplant to prevent rejection of the new organ.
- Having a parent or sibling with the disease.
What can you do to prevent pediatric lymphoma?
Because the known risk factors are not preventable, there are no recommended preventive measures. Some children with risk factors may benefit from genetic testing to determine specific risk.