Lymphoma

Lymphomas are aggressive tumors of the hematopoietic system that can also occur in the brain or spinal cord. The diagnosis is confirmed with the help of tissue sampling. Standard therapy consists of chemotherapy with radiation and depends on the exact diagnosis.

How common are lymphomas?

Generally, there are two types of lymphomas of the central nervous system (CNS):

  1. primary CNS lymphoma (PCNSL) which exclusively affects the brain, meninges, eyes or spinal cord.
  2. secondary CNS lymphoma which are metastases of lymphomas in other organs.

In secondary lymphoma, the affected person has a tumor of the hematopoietic organs that first affects various lymph nodes or the spleen and only metastasizes to the central nervous system in a second step.

PCNSL accounts for approximately 4% of primary tumors of the central nervous system. Patients aged 45 to 65 years are most frequently affected. In this age group, there has been a slight decrease in the last two decades. In contrast, older people are becoming increasingly affected.

In general, the frequency of lymphomas compared to other brain lesions has increased in recent decades. Most affected are patients with a compromised immune system whose life expectancy could be prolonged with the help of modern therapies. These include patients with immunosuppressive therapies for cancer, AIDS, and patients after organ transplantation.

Very few patients with systemic lymphoma disease (non-Hodgkin's lymphoma or NHL) have central nervous system involvement at the time of diagnosis. The exact incidence varies from 3–50% depending on the subtype of lymphoma.

What are the causes of lymphoma?

Lymphomas are tumors that arise from degenerated cells of the hematopoietic system. The causes for the development of a PCNSL are largely unknown. It is thought that the immune system plays an important role, as a PCNSL is not systemic. There is also a possible link with Epstein-Barr virus (EBV), although the virus is far from being identified in all PCNSL patients.

Immunodeficiency is considered the greatest risk factor for the development of a PCNSL. Patients develop such immunodeficiency, for example, in the course of immunosuppressive therapy after organ transplantation or after HIV infection. However, there are also congenital immunodeficiencies. Other diseases associated with PCNSL include lupus erythematosus, rheumatoid arthritis, and inflammatory diseases of the blood vessels (vasculitides).

In secondary CNS lymphomas, the cells enter the CNS by spreading through the bloodstream or by direct infiltration from adjacent bone marrow.

What symptoms does lymphoma cause?

Lymphomas of the central nervous system manifest themselves in most cases (> 50%) by non-specific symptoms such as mood and personality changes as well as signs of increased intracranial pressure such as headache, fatigue, nausea and vomiting. Furthermore, lymphoma is manifested by epileptic seizures in about 10% of patients. About one third of patients also experience focal symptoms such as hemiplegia and impairment of cranial nerve functions (double vision, taste and smell impairments).

How is lymphoma diagnosed?

With the imaging methods of computed tomography (CT) and magnetic resonance imaging (MRI), lymphomas are often difficult to distinguish from other tumors of the nervous system. This is where modern neurosurgery can make an important contribution.

Biopsy

A tissue biopsy with subsequent histopathological examination is an essential step for definitive diagnosis and planning of further treatment. Discuss with our specialists which procedure is most likely to be suitable for you:

  • Stereotactic biopsy is an elegant, minimally invasive neurosurgical procedure for the gentle and millimeter-precise removal of brain tissue.
  • Alternatively, another image-guided, computer-assisted 3D navigation method can be used for millimeter-precise sampling with the so-called VarioGuide.
  • In the case of superficial involvement, a biopsy may also be taken under visual inspection during a small craniotomy (open biopsy).

Stereotactic biopsy offers one of the safest and most effective methods for diagnosing CNS lymphoma. As the most common complication of this procedure, cerebral hemorrhage may occur in rare cases (< 1%). With open biopsy, the complication rate for bleeding, infection, or the like is somewhat higher due to the increased invasiveness. In rare cases, the fine tissue examination after a biopsy does not lead to a conclusive result, which may result in a repeat biopsy.

Histopathological examination and molecular typing of the tumor tissue after a biopsy are performed in the Department of Neuropathology. They provide clarity about the exact diagnosis. Lymphoma can be clearly distinguished from other brain tumors in this way.

Systemic diagnostics

A complete diagnosis also includes a systemic tumor search. This involves a targeted search for tumors at typical sites of origin of lymphomas using CT. These include the lymph node stations in the neck, chest, groin and pelvis. In addition, an analysis of the cerebrospinal fluid (CSF) is performed.

How is lymphoma treated?

Unlike other tumors of the nervous system, lymphoma cannot be surgically removed, but must be treated by administering highly effective chemotherapeutic agents in combination with radiation therapy.

Why you should seek treatment at Inselspital

At the Neurocenter of Inselspital, the planning and implementation of optimal treatment is done by a multidisciplinary team of specialists in neurosurgery, neuroradiology, neuropathology, oncology and radiation oncology with experience in the diagnosis and treatment of this disease. This interdisciplinary team meets weekly as part of a lymphoma board and determines the best possible treatment strategy for each patient individually.

Further reading