CNS Lymphoma: Specialists & Information

The nerve structures in the brain and spinal cord are collectively referred to as the central nervous system (CNS). They are responsible for the central processing of sensory input in humans.

CNS lymphoma is a type of cancer that

• in the brain,
• in the cerebrospinal fluid, or
• the spinal cord

. Occasionally, the eyes are also affected in the form of infiltration of the retina, uvea, or vitreous body. However, with an incidence of only about 10 percent, this is the rarest form of CNS lymphoma.

CNS lymphomas, which are classified as non-Hodgkin lymphomas, are divided into primary and secondary CNS lymphomas.

If, at the time of the initial diagnosis, tumor cells are found exclusively in the central nervous system, the condition is referred to as a primary CNS lymphoma. A secondary CNS lymphoma consists of metastases in the central nervous system. Metastases are secondary tumors that originate from a primary tumor that first developed elsewhere in the body.

The most common type, accounting for over 95 percent of cases, is diffuse large B-cell lymphoma. It is considered “highly malignant,” meaning it is particularly aggressive and grows rapidly. Other B-cell or T-cell lymphomas, on the other hand, are very rarely diagnosed in the central nervous system.

How lymphocytes become malignant and form tumors is still largely unknown. However, researchers suspect that the cause may lie in the production of certain proteins in the central nervous system. These proteins may trigger an uncontrolled immune response that promotes the proliferation of lymphoma cells.

The risk factors for CNS lymphoma have also not yet been conclusively and fully researched. However, the majority of those affected by lymphoma in the central nervous system are adults. Just over half of patients are already 60 years of age or older at the time of initial diagnosis. Men are affected slightly more often than women. There is no evidence of a familial clustering of the disease.

The vast majority of patients with a CNS tumor did not have a weakened immune system prior to the onset of the disease. Nevertheless, this is considered one of the major risk factors: suppression of the body’s immune system (immunosuppression) can lead to the development of lymphoma in the central nervous system.

It is irrelevant whether

• the immunosuppression was induced as a targeted therapy (such as after an organ transplant) or
• it resulted from a disease (such as the Epstein-Barr virus (mononucleosis), human herpesvirus type 8, or HIV infection).

The symptoms associated with CNS lymphoma can vary widely. They depend on the size of the tumor and its exact location within the central nervous system.

The following symptoms are most commonly associated with CNS lymphoma:

• More than half of those affected exhibit what is known as a brain-organic psychosyndrome: these are mental abnormalities that suddenly appear for the first time. These include, for example,
  • impaired memory,
  • lack of interest and indifference,
  • anxiety,
  • fatigue,
  • emotional and behavioral changes, as well as
  • neurological disorders such as paralysis, dizziness, or speech difficulties.
• More than 50 percent of patients complain of headaches and pain that moves around to different parts of the body.
• About one-third of those affected suffer from nausea as a result of increased intracranial pressure, sometimes accompanied by vomiting.
• In rare cases, seizures, night sweats, fever, or weight loss may also occur.
• Vision is impaired when CNS lymphoma affects the eyes.

The initial diagnosis of CNS lymphoma is usually made relatively quickly. This is primarily because the tumor grows relatively fast and the symptoms progress accordingly.

However, some of the symptoms are also typical of other diseases of the central nervous system. If the symptoms are not particularly severe and are rather nonspecific, a diagnosis may sometimes take a little longer.

If a brain disorder is suspected, a head scan using computed tomography (CT) is usually performed. If the doctor detects a tumor during this scan, the next step is to determine as quickly as possible what type of tumor it is and how far the disease has already progressed.

This is followed by

• neurological examinations,
• blood tests, and
• a cerebrospinal fluid (CSF) sample.

Magnetic resonance imaging (MRI) provides the most informative results. However, the images do not allow for an unequivocal identification of the brain tumor type. A tissue sample of the lymphoma is required for a definitive diagnosis.

Magnetic resonance imaging can clearly visualize a CNS lymphoma in the brain © Chinnapong | AdobeStock

The tissue sample is obtained via stereotactic biopsy using a hollow needle inserted through a tiny drill hole in the skull. This procedure is the most common method today.

After a diagnosis of CNS lymphoma, doctors look for additional lymphoma sites in the body. This is aided by

• a CT scan of the torso,
• a bone marrow aspiration, and
• in men, an ultrasound examination of the testicles.

Finally, it could also be a secondary CNS lymphoma—that is, a metastasis from another tumor.

Without any treatment, a CNS lymphoma would lead to death within a short period of time. Therefore, swift action is required.

However, complete surgical removal—as is often performed for other brain tumors—is not effective for CNS lymphoma. A combination of chemotherapy and radiation therapy, or chemotherapy alone, offers better long-term prospects for success.

Depending on the patient’s age, both the efficacy and the side effects of the respective treatment modality vary. For this reason, a treatment plan tailored to the individual must always be followed. A distinction is made between

• initial therapy (induction therapy) and
• subsequent consolidation therapy to stabilize the patient’s health.

The chemotherapy drug methotrexate is most commonly used in induction therapy. It is also popular because it can be administered to patients of all ages. The drugs cytarabine, ifosfamide, and thiotepa are also effective.

As a supplement to chemotherapy, doctors often opt for antibody therapy (known as chemoimmunotherapy when used in combination). In this approach, the active ingredient rituximab binds to the surface structures of the tumor cells, thereby triggering their destruction.

Consolidation therapy may include

• radiation therapy,
• conventional chemotherapy, or
• high-dose chemotherapy followed by autologous stem cell transplantation (abbreviated as HDT-ASZT)

be used. However, radiation therapy can have neurological consequences, such as impaired memory or a reduced quality of life. For this reason, the alternatives should be preferred whenever possible.

HDT-ASZT, in particular, has often led to very good long-term outcomes to date. In this procedure, stem cells are harvested from the patient before chemotherapy and then reinfused afterward.

Specialists in hematology and oncology at established treatment centers are the right point of contact for patients with CNS lymphoma.

The Competence Network for Malignant Lymphomas can assist in the search for experts. Here you will find hospitals and specialist practices with many years of experience in the treatment of CNS lymphoma.

The Federal Association of German Leukemia & Lymphoma Aid (Bundesverband Deutsche Leukämie- & Lymphom-Hilfe e.V.) brings together self-help organizations for people with leukemia and lymphoma. Here you can search for the self-help group nearest to you. In addition, a wide range of brochures, literature, and event information is available.

Although CNS lymphoma is considered particularly aggressive, the disease can be kept in check for several years with a treatment plan optimally tailored to the patient.

In younger patients with a well-functioning immune system, a complete cure may even be possible.