Gliomatosis cerebri (GC) refers to a certain growth pattern of a glial tumor that is widespread and affects multiple sections of the brain.

GC is a tumor that begins in the central nervous system (CNS), either in the brain or spinal cord. It is no longer a formal diagnosis but refers to a certain growth pattern. GC is a widespread glioma that spreads to multiple sections, or lobes, of the brain.

A glioma, or glial tumor, is a tumor that forms in brain and spinal cord cells called glial cells. Different types of gliomas can grow with a GC growth pattern.

This article explains the GC growth pattern’s symptoms, diagnosis, treatment, and typical outlook.

A person with the gliomatosis cerebri brain tumor growth pattern holding their head due to pain.-2Share on Pinterest
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Symptoms of GC may depend on a person’s age and the location of the tumor but can include:

There is no known cause of GC, but as a type of cancer, it occurs through genetic changes. Gene mutations can result in cancerous cells, which can grow and spread to form tumors.

GC is slightly more common in males than females. It is more likely to occur in older adults but can affect anyone of any age.

Experts are unclear on risk factors for gliomas. However, radiation exposure, such as through radiation therapy, is a risk factor for brain tumors, including gliomas.

Hereditary gene mutations frequently occur with gliomas. A small number of gliomas may also occur with certain syndromes, such as:

Medical professionals no longer refer to GC as a formal diagnosis. Instead, they refer to it as a growth pattern.

The 2016 World Health Organization (WHO) Classification of CNS Tumors categorizes GC as a subtype of diffuse gliomas.

The classification defines GC as more than two affected lobes of the brain on an MRI scan, with little to no contrast dye to enhance the imaging scan.

GC is not an individual entity but consists of different forms and grades of primary brain tumors.

A neuropathologist, a doctor specializing in diseases of nervous system tissue, will analyze the tumor tissue from a biopsy to grade a primary CNS tumor.

Gliomatosis cerebri grading

The grading of the primary tumor determines the grade of GC, which is as follows:

  • Grade 2: Low grade tumors that are slow-growing and may respond better to treatment.
  • Grade 3 and 4: High grade tumors that are fast-growing and have a greater resistance to treatment.

Doctors use an MRI scan to identify GC. GC usually involves three or more lobes of the brain on an MRI scan, which doctors classify into two types depending on the appearance of the tumor:

  • Type 1: A widespread pattern or abnormality with a fluffy appearance but no clear mass.
  • Type 2: A widespread pattern with a fluffy appearance, with a tumor mass.

If possible, the first-line treatment for GC is surgery to remove as much of the tumor as possible. Surgery usually takes the form of a biopsy to remove the cancerous tissue. As GC is widespread, doctors are often unable to remove the tumors as one mass.

After surgery, treatment may depend on the individual’s circumstances. Treatments may include chemotherapy and radiation therapy.

GC may respond well to radiation therapy. However, there are risks, as the widespread nature of GC means a large area of the brain, including healthy tissue, is at risk of radiation exposure.

People may also have chemotherapy alongside or after radiation therapy. Chemotherapy is also an option if GC recurs after the first treatment. Doctors may use the chemotherapy drug temozolomide (Temodar).

People may also want to discuss clinical trials with a doctor. Taking part in clinical trials may give people access to newer chemotherapy treatments or other treatments such as immunotherapy or targeted therapy.

Data from 2008 to 2018 suggests the five-year relative survival rate for GC is 16.5%. Various factors can affect outlook, including the grade and type of tumor, treatment response, age, and overall health.

A five-year relative survival rate refers to the likelihood of a person with a certain condition surviving for five years after diagnosis compared to someone without that condition.

GC can quickly spread through the CNS and reach deep into brain tissue. In rare cases, it may spread through cerebrospinal fluid or into the spine. GC does not spread outside of the CNS.

According to a 2018 article, some people with GC may have highly favorable survival times. The article suggests doctors should base a person’s outlook on molecular markers rather than just features appearing on imaging scans.

Certain molecular markers, such as specific gene mutations, in gliomas may link to improved survival in people with GC. Some reports show people with GC surviving 3 to 7 years.

Experts currently understand very little about the genetic process and origin of GC. Further research is necessary to better understand the disease and improve treatment, which may help improve the outlook.

GC is no longer an official diagnosis but refers to a growth pattern of a glial tumor that is widespread throughout the brain. On an MRI scan, GC affects more than two lobes of the brain.

Due to the widespread growth of GC, it can be challenging to treat with surgery. Doctors will aim to safely remove as much of the tumor as possible. Treatment may then include chemotherapy and radiation therapy. People may want to consider taking part in clinical trials with new treatments.

GC is fast-growing, so it can spread quickly. The outlook for GC may depend on various factors, such as age, overall health, tumor type and grade, and treatment response.