Gangliocytoma

Gangliocytomas 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 most gangliocytomas are benign, in very rare cases they may become malignant.

The brain is a complex organ that is responsible for controlling all functions of the body. It has five main portions: the cerebrum, cerebellum, brainstem, pituitary gland, and hypothalamus. The cerebrum is the biggest part of the brain, and consists of the frontal, parietal, temporal, and occipital lobes. This part of the brain is responsible for voluntary movement, intelligence, and memory. The cerebellum is a small part of the brain located at the back of the head, and regulates posture and balance. The brainstem is a small, stalk-like structure towards the bottom of the brain that connects the brain to the spinal cord.  It regulates many vital bodily processes, such as swallowing, breathing, and heart rate. The pituitary gland is a pea sized organ located behind the eyes, and is responsible for the production and secretion of hormones in the body. The hypothalamus is located deep within the brain, and has many important functions, such as producing and secreting different hormones, regulating temperature, and controlling appetite.

The spinal cord is a long, thin, tubular structure that extends down from the brainstem to the lower back. It is made of nerve tissue, and is surrounded by the bones of the spine (vertebrae). The spinal cord is responsible for transmitting nerve signals from the brain to the body, and vice versa. It has motor functions (such as voluntary movement), sensory functions (such as pressure, touch, temperature, and pain), and autonomous functions (such as regulating digestion, heart rate, and blood pressure).

Gangliocytomas are most commonly found in the temporal lobe of the cerebrum, but can also develop in the cerebellum, brainstem, and spinal cord. Initially, they may be confused with ganglioglioma as they are indistinguishable on imaging scans.

Gangliocytomas are generally diagnosed equally among the sexes, and are most commonly found in people between the ages of 10-30. However, anyone can develop this disease.

Types of Gangliocytoma

Because of how rare gangliocytomas are, only one variant of this disease has been identified.

Lhermitte-Duclos Disease

Lhermitte-Duclos disease, also known as dysplastic cerebellar gangliocytoma, is a very rare condition that is characterised by the abnormal development and enlargement of the cerebellum portion of the brain. It is often accompanied by increased intracranial pressure, and has been associated with a hereditary cancer syndrome known as Cowden syndrome. Unlike most gangliocytomas, Lhermitte-Duclos disease is most commonly diagnosed in people between the ages of 30 and 40. This tumour is often non-aggressive, slow growing, and can have a good prognosis.

For more information on Lhermitte-Duclos disease, please refer to the Rare Cancers Australia Lhermitte-Duclos disease page.

Treatment

When cancers are detected, they are staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging 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 from I-IV.

Gangliocytomas are generally benign, and are often classified as a grade I tumour. Grade I (low grade) tumours have cells that present as slightly abnormal, and are usually slow growing.

Once your tumour has been graded, your doctor may recommend genetic testing, 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 gangliocytomas may include:

  • Surgery to remove as much of the tumour as possible.
  • Watch and wait.
  • Radiation therapy.
  • Clinical trials.
  • Palliative care.

Risk factors

Because of how rare gangliocytomas are, there has been limited research done into the risk factors of this disease. However, Lhermitte-Duclos disease has been linked to people with Cowden syndrome.

Symptoms

Gangliocytomas may appear asymptomatic in the early stages of disease. As the tumour progresses, some of the following symptoms may appear:

  • Epilepsy (most commonly temporal lobe epilepsy (TLE)).
  • Increased intracranial pressure.
  • Hydrocephalus.
  • Headaches.
  • Blurred or double vision.
  • Nausea and/or vomiting.
  • General feeling of weakness.
  • Behavioural changes.
  • Difficulties with moving and/or talking.
  • Lack of energy.
  • Fatigue.
  • Hypertension.
  • Confusion and/or lack of alertness.
  • Endocrine disorders.
  • Focal signs.

In addition to these symptoms, patients with Lhermitte-Duclos disease may also experience:

  • Megalencephaly.
  • Hydromyelia.
  • Polydactyly.
  • Partial giantism.
  • Macroglossia.

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 an gangliocytoma, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:

  • Physical examination.
  • Neurological examination.
  • Imaging tests, potentially including:
    • MRI (magnetic resonance imaging).
    • CT (computed tomography) scan.
  • Blood tests.
  • Biopsy.

References

Keep up with Rare Cancers Australia

Inside Rare is a monthly newsletter that shares the latest news, events and stories connecting the rare community.