Lymphomas in childhood Dr Trisha Macnair Lymphoma is a cancer of the lymphatic system, the system that helps the body fight infection. There are two main types: Hodgkin lymphoma and non-Hodgkin lymphoma.

In this article

What are lymphomas? Symptoms

Causes and risk factors Treatment and recovery

Advice and support

Lymphoma affects the lymphatic system. This consists of thin tubes called lymph vessels that run throughout the body, carrying lymph, a colourless, watery fluid that contains white blood cells called lymphocytes. Dotted along the lymph vessels are groups of small, bean-shaped lumps called lymph nodes or glands. Clusters of lymph nodes are found under your arms, around your neck and under your chin, and throughout the pelvis, groin, abdomen and chest. They make and store infection-fighting cells, especially lymphocytes.

Lymphoma results when a lymphocyte undergoes a malignant change and multiplies, eventually crowding out healthy cells and creating tumours. These tumours enlarge the lymph nodes and/or grow in other sites that are part of the immune system.

Lymphoma accounts for one in ten childhood cancers, it is the third most common cancer in childhood. Lymphomas are divided into Hodgkin lymphoma and Non-Hodgkin lymphoma. Non-Hodgkin is more common in young children, and Hodgkin lymphoma is more common in adolescents. Lymphomas are twice as common in boys than girls.

There may be no symptoms until the lymphoma has spread. Lymphoma can start in almost any part of the lymphatic system and spread to almost any other part of the body, including the liver, bone marrow (the spongy tissue inside the large bones of the body that makes blood cells) and the spleen (an organ in the upper abdomen that makes lymphocytes and filters old blood cells from the blood).

Hodgkin lymphoma usually presents with painless swelling of the lymph nodes (lymphadenopathy), most frequently in the neck. Often people get a similar swelling (lymphadenopathy) if they have a simple cold. However, in Hodgkin lymphoma the swelling is much larger and firmer.

Other symptoms (called ‘B’ symptoms) are:

• Fever for which no cause can be found
• Fatigue or extreme tiredness
• Paleness
• Night sweats (usually a sign of Hodgkin's)
• Weight loss

Often lymphomas have spread all over the body before the person is aware they have a problem.

The exact cause of lymphoma is uncertain. Scientists have looked at many things that may be linked with lymphomas. They have found many connections and risk factors but are unable to say exactly what the causes are.

Exposure to certain viruses and bacteria is associated with lymphoma (For example, it may be that Epstein-Barr virus may increase the risk of getting lymphoma and people with HIV have an increased risk of getting lymphoma).

Genetic and environmental factor, such as exposure to pesticides, have also been implicated.

The two main types of lymphoma involve different types of white blood cell and it's important to get the exact diagnosis - determined mainly by what the cells look like under the microscope.

Each type of lymphoma needs slightly different treatments and has different prognoses or cure rates. Doctors will also 'stage' the tumour - this means working out how far it has spread around the body.

As recently as 1950, lymphoma was almost inevitably fatal, but these days over 90 per cent of those newly diagnosed with Hodgkin lymphoma can expect to be cured. Non-Hodgkin lymphoma is less easily treated, with an overall cure rate of about 75 per cent.

Lymphomas are usually treated by a combination of chemotherapy, radiation, surgery and/or bone marrow transplants. The main treatment is chemotherapy, in which drugs are used to kill cancer cells and shrink tumours.

Radiotherapy involves the use of high-energy x-rays to kill the cancer cells. Bone marrow transplantation is a newer type of treatment, which allows very high doses of anti-cancer drugs to be given.

Many children with lymphoma will be offered the chance to be treated as part of a clinical trial. While they or their family may be frightened by the idea that they're being used as some sort of guinea pig, they'll be very carefully monitored by doctors during the trial. Trials are the only way to find better treatments.

Lymphoma Association

Helpline: 0808 808 5555
Email: information@lymphoma.org.uk
Website: www.lymphoma.org.uk

This article was last medically reviewed by Dr Orlena Kerek in February 2009