Hodgkin lymphoma develops from B lymphocytes, which are cells of the immune system. It is characterized by the presence of specific tumor cells, called Hodgkin and Reed-Sternberg cells, within an environment composed of numerous inflammatory cells.

The disease most often affects the lymph nodes, particularly in the neck and chest. It can also affect the spleen and, more rarely, other organs. In children, it is rare before the age of 5 and becomes more common during adolescence.

In most cases, no specific cause is identified. A previous infection with the Epstein-Barr virus may be associated with certain types of Hodgkin lymphoma, but the vast majority of people who have been exposed to this virus will never develop lymphoma.

Factors related to the functioning of the immune system and genetic susceptibility may play a role. Hereditary forms of the disease remain rare. The disease is not caused by lifestyle, diet, upbringing, or psychological factors.

The most common symptom is a persistent enlargement of one or more lymph nodes, often in the neck. These lymph nodes are generally painless and develop gradually.

Lymph Node Biopsy

The diagnosis is based on the analysis of a lymph node or tissue sample. Whenever possible, a biopsy that allows for examination of the lymph node’s architecture is preferred. The pathologist looks for Hodgkin and Reed-Sternberg cells and determines the lymphoma subtype.

A simple blood test cannot confirm or rule out the diagnosis. However, it assesses the patient’s overall condition, checks for an inflammatory syndrome, and provides useful information prior to treatment.

Staging Evaluation

Fluorodeoxyglucose (FDG) PET-CT plays a central role in identifying active disease sites, determining the stage of the disease, and providing a baseline examination prior to treatment. A diagnostic CT scan or other imaging tests may be used to supplement this, depending on the situation.

The disease is classified based on the affected lymph node regions, their position relative to the diaphragm, any organ involvement, tumor volume, and the presence or absence of B symptoms. A bone marrow aspiration or biopsy is no longer routinely performed when PET provides the necessary information.

European pediatric treatment guidelines are organized by treatment groups. They tailor the number and type of chemotherapy cycles to the initial extent of the disease, risk factors, and early response. The goal is to achieve a cure while reducing the risk of cardiac, endocrine, pulmonary, and gonadal complications, as well as the risk of secondary cancers.

Chemotherapy

Chemotherapy is the primary treatment. The drug combinations used in children and adolescents differ from those used in adults and are selected to maintain efficacy while minimizing certain toxicities, particularly gonadal toxicity. The number of treatment cycles depends on the treatment group and the response.

Early Response Assessed by PET

After the first few cycles, a PET scan assesses the metabolic response. This step is critical: a sufficiently good response may make it possible to avoid radiation therapy in certain situations. An insufficient response leads to a discussion about adjusting the treatment and the indication for targeted radiation therapy.

Radiation Therapy

Radiation therapy is not routinely administered. When indicated, it targets the initially affected sites that require additional treatment, using appropriate treatment volumes and doses. Modern techniques aim to provide the best possible protection for the heart, lungs, thyroid, breasts, and other healthy tissues.

When a lymphoma does not respond adequately to initial treatment or recurs, a new biopsy may be considered, and the treatment strategy depends on the time to relapse, the treatments already received, the affected sites, and the response to salvage therapy.

Treatment may include salvage chemotherapy, brentuximab vedotin—which targets CD30—or anti-PD-1 immunotherapy such as nivolumab. In certain situations, high-dose chemotherapy followed by an autologous stem cell transplant remains the recommended approach. Other patients, particularly those with certain low-risk relapses, may benefit from tailored strategies evaluated in specialized clinical trials.

After treatment ends, follow-up care ensures that remission is maintained, monitors for any late effects, and supports the patient’s return to daily life. It is primarily based on follow-up visits, clinical examinations, and symptoms. Imaging tests are ordered according to the protocol and the patient’s situation, in order to avoid unnecessary radiation exposure.

The Department of Pediatric and Adolescent Oncology treats patients up to age 25 and provides care tailored to children, adolescents, and young adults. Each case is discussed during a multidisciplinary team meeting, drawing on the expertise of pediatric oncologists, hematologists, pathologists, radiologists, nuclear medicine specialists, radiation oncologists, and palliative care professionals.

The care plan may include psychological support, pain and nutrition management, adapted physical activity, support for continuing school or college, social support, fertility preservation, and long-term follow-up.

The research aims to maintain very high cure rates while reducing toxicity. In particular, it evaluates the use of PET-guided treatment, the reduction of radiation therapy, the integration of targeted drugs and immunotherapies, as well as less toxic catch-up strategies.