The lymphatic system contains lymphocytes (which are a type of white blood cell), responsible for defending our body against infections, and lymph nodes (or lymph glands), which function as a reservoir of various immune system cells. Lymphoma is a cancer that occurs when lymphocytes and their precursors belonging to the lymphatic system become malignant and grow in an uncontrolled way.
This disease ranks third among the most common cancers in childhood, behind only brain tumors and leukemias. There are different types of lymphomas, some grow very slowly and others much faster.
Of childhood cancers, 7% are non-Hodgkin’s lymphomas (NHL) and 6% are Hodgkin’s lymphomas (HL).
Patients with lymphoma have a high probability of cure with current therapeutic regimens – provided that the diagnosis is early and with a low degree of spread of the disease.
Types of lymphoma
There are two types of lymphoma: Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL), which present different behaviors, signs and degrees of aggressiveness. The severity, in both types, will depend on the stage (degree of spread of the disease) in which the lymphoma is detected.
- Hodgkin’s Lymphoma – can arise in any part of the body where lymphoid tissue is widely distributed. In any case, the most frequent locations for the appearance of lymph nodes (bubo) are the chest, neck and armpit. Patients with Hodgkin’s lymphoma are highly likely to be cured, and adolescents are more likely to have Hodgkin’s lymphoma than are young children;
- Non-Hodgkin lymphoma – after diagnosis, the disease is classified according to the type of lymphoma and the stage it is in (they are grouped according to the type of lymphoid cell affected, whether B or T lymphocytes). Also considered for classification are the size, shape and pattern of presentation of cancer cells under the microscope. This information is important to properly select the form of treatment.
About 60% of cases of lymphoma in children and adolescents are non-Hodgkin’s lymphoma, and the chances of cure range from 60% to 90%, depending on the clinical characteristics of each patient. Non-Hodgkin lymphomas in children are usually of three types:
- Lymphoblastic lymphoma – accounts for about 25% to 30% of lymphomas in children and adolescents, with an incidence in boys twice as high as in girls. Most cases develop from T cells and can grow rapidly;
- Burkitt’s Lymphoma – represents about 40% of lymphomas in children and is more frequent in boys between ages 5 to 10. It almost always starts in the abdomen and, as its growth is fast, it is very important to start treatment as soon as possible; and
- Large cell lymphoma – can grow anywhere in the body and is most common in teenagers. It has two subtypes: anaplastic large cell lymphoma (generally start in the skin, lungs, bones, digestive system, or other organs) and diffuse large B-cell lymphoma (begin as a rapidly growing mass in sites such as the thoracic-mediastinum region, abdomen, neck and bones).
Symptoms and signs of lymphoma
Symptoms are the same for Hodgkin’s lymphoma and non-Hodgkin’s lymphoma. The main signs of the disease are:
- Enlarged lymph nodes in the neck, groin and armpits;
- Fever and fatigue;
- Night sweat;
- Weight loss for no apparent reason;
- Increased volume in the chest and abdomen;
- Cough, shortness of breath and pain in the chest area;
- Enlarged spleen (splenomegaly); and
- Itchy skin (pruritus).
During the consultation, the doctor asks about the symptoms that the child presents, and in the physical examination, the presence of lymph nodes in regions such as the armpits, neck and groin is investigated. If any are found, tests will be requested to confirm the diagnosis.
Exams are also requested to assess the patient’s general health status and check for other diseases that present manifestations similar to lymphomas.
The other exams are usually:
- Lymph node biopsy: the lymph node is surgically removed and sent for analysis in the laboratory. It is the test that confirms whether or not it is a lymphoma;
- Bone marrow biopsy: when requested, the procedure includes removing a small fragment of bone in the lower back using a needle. With this, it will be defined if the organ was also affected by the disease;
- Computed tomography: the equipment has a table on which the patient lies for the exam, which allows the identification of enlarged lymph nodes throughout the body and makes it possible to assess the spread of the disease;
- Magnetic resonance imaging: method that uses electromagnetic waves for image formation, which allows an evaluation of internal organs. It is used less often than CT scans; and
- PET scan: allows you to identify other parts of the body that may be affected by lymphoma and check whether the enlarged lymph nodes are diseased or benign. It is also performed to show the response to ongoing treatment.
Lymphoma treatment in children
The treatment of lymphoma in children and adolescents can have excellent results, and the chances of cure exceed 80%. Approaches are mainly based on chemotherapy, radiotherapy, stem cell transplants and immunotherapies. Understand each of them better:
- Chemotherapy – treatment that uses drugs to destroy, control and inhibit the growth of diseased cells. It can be taken orally or with application through a catheter. Another alternative is intrathecal, when it is necessary for the lymphoma treatment to reach the central nervous system, directly through the spinal fluid. Regardless of the type, some side effects may arise, such as nausea, diarrhea, constipation, change in taste, dry mouth, mouth wounds and difficulty swallowing;
- Radiotherapy – used in some cases, with radiation destroying or inhibiting the growth of abnormal cells that form a tumor;
- Bone marrow transplantation – also called hematopoietic stem cell transplantation, this option is indicated when the treatment is not achieving the expected result. If the bone marrow is not affected, the patient himself will be the donor, in the so-called autologous transplant.
In a surgical environment, stem cells are collected through a vein or by direct collection of bone marrow, frozen and stored (cryopreservation). After collection and cryopreservation, the patient undergoes a high-dose chemotherapy regimen, called conditioning, which aims to eliminate all cells. This chemotherapy regimen consequently leads to bone marrow destruction. Therefore, after chemotherapy, stem cells previously collected are thawed and infused into the patient.
When the bone marrow starts working again (around 2 to 4 weeks after the infusion) it can be said that the marrow has taken up; and
- Immunotherapy – antibodies are proteins produced by the immune system to fight infections, and monoclonal antibodies, also known as immunotherapy, are produced in the laboratory with the aim of acting on a specific target. With this, immunotherapy makes the immune system itself recognize the diseased cells and attack them. Some possible side effects are chills, fever, nausea, rashes, fatigue, and headaches.
Prevention of lymphoma in children
Most children with lymphoma have no known risk factors that can be changed, so there is no way to protect yourself against lymphoma.
Patients at high risk of developing Hodgkin’s or non-Hodgkin’s lymphoma are those who have a compromised immune system – as a result of genetic diseases, HIV infection or use of immunosuppressive drugs – or who have family members diagnosed with the disease.