Focal brainstem gliomas are a rare type of brainstem glioma that develops from glial (or supportive) tissuea group of cells that work together to perform a function in the brain, which supports and protects the brains neurons. More specifically, it develops in the midbrain or medulla portions of the brainstem, which is found at the base of the brain.
The brainstem is a thin, stalk-like structure that connects the brain and the spinal cord. It is divided into three sections: the midbrain (or mesencephalon), pons (or metencephalon), and medulla (or medulla oblongata). Each component of the brainstem works together to control and regulate vital bodily functions, such as breathing, heart rate, bloodthe red bodily fluid that transports oxygen and other nutrients around the body pressure, as well as the nerves and muscles used for seeing, hearing, walking, talking, and eating.
There are two main types of brainstem gliomas in children: Diffuse Intrinsic Pontine Glioma (DIPG) and focal brainstem gliomas. Focal brain stem gliomas are well-contained and generally only found in one area. These tumours are generally benignnot cancerous, can grow but will not spread to other body parts or low gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells, and often has a better prognosisto predict how a disease/condition may progress and what the outcome might be than DIPG. Comparatively, DIPG has a diffuse nature, which means the tumoura tissue mass that forms from groups of unhealthy cells is spread out and difficult to treat. These tumours are more common, but generally don’t have as good of a prognosis. For more information on DIPG, please refer to the Rare Cancers Australia DIPG page.
Focal brainstem gliomas are almost exclusively diagnosed in children, most commonly between the ages of five and nine. However, anyone can develop this disease.
Types of Focal Brainstem Gliomas
There are three primary subtypes of focal brainstem gliomas, which are classified by the type of cellsthe basic structural and functional unit of all living things the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs develops from.
Pilocytic Astrocytoma
Pilocytic astrocytoma, also known as juvenile astrocytoma, is a slow growing subtype of astrocytoma that primarily affects children. It is classified as a grade I tumour, and develops slowly over time. Pilocytic astrocytomas generally non-aggressive, and often has a good prognosis. For more information on pilocytic astrocytomas, please refer to the Rare Cancers Australia Astrocytoma page.
Ganglioglioma
Gangliogliomas are rare types of tumours that generally develop in the central nervous system (CNS). More specifically, they develop from ganglia in the CNS, which are a group of neuronal bodies which sends messages to the brain relating to touch, smell, taste, sound, and visual stimuli. While gangliogliomas are generally benign (non-cancerous), in rare cases they may become malignantcancerous, may grow and spread to other areas of the body (cancerous). For more information on gangliogliomas, please refer to the Rare Cancers Australia Ganglioglioma page.
Oligodendroglioma
Oligodendrogliomas are a common type of glioma, which develop from the glial (or supportive) cells in the central nervous system (CNS). More specifically, they develop from a type of glial cell called oligodendrocytes, which produce a fatty, white substance known as myelin. For more information on oligodendrogliomas, please refer to the Rare Cancers Australia Oligodendroglioma page.
Fibrillary Astrocytoma
Fibrillary astrocytomas are a common type of diffuse astrocytoma, and a less common type of focal brainstem glioma. This type of cancer is generally classified as a grade II tumour, is widespread, and has poorly defined borders (diffuse). This type of tumour can be aggressive, and can have a good prognosis when found early. For more information on diffuse astrocytomas, please refer to the Rare Cancers Australia Astrocytoma page.
Glioblastoma
Glioblastomas, also known as glioblastoma multiforme (GBM), are a common type of brain tumour, but a rare type of focal brainstem glioma. Its name is derived from its cellular appearance under the microscope, which is often highly varied. GBM is generally classified as a high-grade brain tumour, are often highly aggressive tumours, and may not have as good of a prognosis as other types of focal brainstem glioma. For more information on GBM please refer to the Rare Cancers Australia Glioblastoma page.
Treatment
When cancers are detected, they are staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you. However, brain cancers are rarely staged, as they rarely spread to other parts of the body. Instead, they are generally graded.
Focal brainstem gliomas are generally graded by subtype:
- Grade I (low-grade) tumours: cancer cells present as slightly abnormal and are usually slow growing. Includes the subtypes pilocytic astrocytoma, ganglioglioma and oligodendroglioma.
- Grade II (intermediate-grade) tumours: cancer cells present as abnormal and grow faster than grade-I tumours. Includes fibrillary astrocytoma.
- Grade III/IV (high grade) tumours: cancer cells present as very abnormal and grow quickly. Includes glioblastoma/GBM.
Your doctor may also recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, age, stage of disease and overall health.
Treatment options for focal brainstem gliomas may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence to remove as much of the tumour as possible (may not always be an option).
- Shunt insertiona procedure to relieve build-up of cerebrospinal fluid (CSF) in the brain.
- Watch and waitthe close monitoring of a cancer without giving treatment until symptoms appear or worsen.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare focal brainstem gliomas are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease. However, some recent research has suggested that there is a potential link to certain genetic disorders, such as neurofibromatosis type 1 (NF1).
Symptoms
Patients with a focal brainstem glioma may appear asymptomatic in the early stages of disease. As the tumour progresses, some of the following symptoms may appear:
- Problems controlling eye movement, facial expressions, chewing and/or swallowing (as a result of nerve compression in the brain).
- Slurred speech.
- Difficulties with balance.
- Hydrocephalusa build up of cerebrospinal fluid (CSF) in the brain, causing pressure and potentially damaging brain tissue.
- Headaches (often after waking up in the morning).
- Nauseato feel sick or likely to vomit and/or vomiting (generally worse in the morning).
- Irritability.
- Blurred or double vision.
- Seizures.
- Lethargylack of energy, fatigue.
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Changes in eating habits/appetite.
- Difficulty walking.
- Personality changes.
- Enlarged fontanelles (soft spots on an infant’s head between the bony plates of the skull).
- Enlarged head (more common in infants).
- Facial drooping.
- Difficulties urinating.
- Weakness in the arms and/or the legs.
- Clumsiness.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have a focal brainstem glioma, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Neurological examinationan assessment of sensory and motor functions, such as vision, balance and coordination.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
