Lymphomas

Overview: What is lymphoma?

Along the blood vessels, a network of lymphatic vessels runs through the entire body. The lymph fluid (lymph) transports fluid from the tissue to the lymph nodes. In the lymphatic system and other tissues, lymphocytes are responsible for detecting viruses and bacteria and rendering them harmless. In the case of lymphoma, the lymphocytes degenerate and multiply rapidly. This is usually noticeable because the lymph nodes swell considerably.

There are different subtypes of lymphoma:

• Hodgkin’s lymphoma
• Non-Hodgkin’s lymphoma (NHL)

The Hodgkin cells were named after their discoverer, the physician Sir Thomas Hodgkin. The majority of lymphomas are non-Hodgkin’s lymphomas. These include some very different lymphoma diseases. If plasma cells (a subgroup of B lymphocytes) multiply uncontrollably and mistakenly settle in the bone marrow, this is called multiple myeloma.

Forms of lymphoma

We have now recognized that the previous distinction between leukaemia and lymphoma often does not exist in reality and that lymphoma is not always strictly limited to the lymphatic system. At an advanced stage of the disease, degenerated lymphoma cells can be found in the lymph nodes as well as in the blood and bone marrow, especially in non-Hodgkin’s lymphomas.

The World Health Organization (WHO) now differentiates between lymphomas on the basis of the underlying type of lymphocyte:

• B-cell lymphoma: B lymphocytes are degenerated. The most common types are diffuse large B-cell lymphoma, CLL, follicular lymphoma and plasma cell myeloma.
• T-cell lymphoma: T-lymphocytes are degenerated.

Both forms have many sub-forms. For experts, it is important to distinguish between low-malignant lymphomas, which develop slowly over years, and highly malignant lymphomas, which grow rapidly without treatment. In addition, the Ann Arbor classification designates the spread of the lymphoma in the body with four stages (I to IV). Letters are used to indicate the absence (A), the presence of symptoms (B) and an infestation outside a lymph node (E) have been described.

Frequency and age

Overall, lymphomas occur much less frequently than other types of cancer. The incidence of Hodgkin’s lymphoma worldwide is around one new case per 100,000 people per year. Men fall ill slightly more often than women. In Switzerland, around 270 people are diagnosed with Hodgkin’s lymphoma every year, and around 1,600 people are diagnosed with non-Hodgkin’s lymphoma. The average age of onset for non-Hodgkin’s lymphoma is 70 years for men and 72 years for women. In the case of Hodgkin’s lymphoma, there is an additional focus of the disease in 20 to 30-year-olds.

Lymphoma: causes and risk factors

As with all types of cancer, there is no direct trigger for healthy lymphocytes to undergo pathological changes. However, certain viruses are suspected of increasing the risk of lymph node cancer. For example, the HI virus and the Epstein-Barr virus (trigger of Pfeiffer’s glandular fever) appear to favor lymphoma. Changes to the genetic material in the lymphocytes can also trigger this cancer. The genetic information can be altered by

• radioactive radiation,
• Tobacco consumption and
• intensive contact with pollutants.

People with an immune deficiency, such as an HIV infection, are particularly at risk. Anyone who has relatives with lymphoma also has a higher risk of developing the disease.

Symptoms: Lymphoma causes the lymph nodes to swell

The first warning sign of lymphoma is swelling of the lymph nodes that persists over a longer period of time. They usually do not hurt, but often cause a feeling of pressure. In addition, the following symptoms often occur:

• Fever without other cold symptoms
• Heavy sweating at night
• little appetite
• Unexplained weight loss
• Tiredness and exhaustion
• Headache

Depending on which organ the lymphoma cells have affected, other symptoms may also occur: Bone and joint pain, digestive disorders and abdominal pain, breathing difficulties and coughing. However, many of these symptoms also occur with normal colds or other harmless illnesses. Therefore, they alone are not an indication of cancer. However, if they persist for more than two weeks, we should clarify the cause.

Lymphoma: Diagnosis at the USZ

We will first ask you to describe your symptoms and any other possible illnesses. We will then examine whether the lymph nodes or other organs have enlarged. If we then suspect that you may have lymphoma, we will order a blood test and imaging.

To confirm the diagnosis, we take a tissue sample from a suspicious lymph node or the bone marrow. We then examine the tissue under the microscope and for analysis in our specialized laboratories. In the case of cancer, either the characteristic Hodgkin’s cells are visible or other distinctive forms that indicate exactly which lymphoma is involved.

We then find out which organs are affected and how far the lymphoma has spread in the body. We can tell some of this from the composition of the blood. The bone marrow is also often examined for this purpose. To do this, some bone marrow is removed from the pelvic bone with a biopsy. Further information can be obtained using imaging techniques such as ultrasound, X-ray, magnetic resonance imaging (MRI) or computer tomography (CT) and positron emission tomography (PET/CT).

Lymphoma: prevention, early detection, prognosis

You cannot prevent lymphoma. You can only avoid X-rays or contact with toxic substances and tobacco. Early detection is also difficult, as the symptoms are non-specific and also occur in many other diseases. However, anyone who feels clearly enlarged lymph nodes for longer than two weeks should consult us.

Overall, a healthy lifestyle helps to strengthen the body’s defenses against any disease. Plenty of exercise and fresh air as well as a varied diet with lots of fruit and vegetables and little alcohol help.

Favorable prognosis for many forms of lymphoma

If a lymph node is affected by malignant lymphocytes, these sometimes spread rapidly throughout the rest of the body. How quickly the disease progresses and how good the chances of recovery are depends on which subtype is responsible for the symptoms. Low malignant lymphomas, for example, spread very slowly and cause hardly any symptoms. Both Hodgkin’s lymphoma and diffuse large B-cell lymphoma are relatively easy to cure.

Self-help groups

The exchange with people who are affected by the same disease can be a great support in coping with the disease. Advice on finding a suitable self-help group is available from Selbsthilfe Zürich. Self-Help Zurich and the University Hospital Zurich are cooperation partners in the national project “Health literacy thanks to self-help-friendly hospitals”.