Lhermitte-Duclos Disease (LDD)

Lhermitte-Duclos disease (LDD), 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 disease.

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.

LDD is generally considered benign, however as all gangliocytomas, they can become malignant in very rare cases.

LDD tends to affect the sexes equally, and is generally diagnosed between the ages of 30-50. However, anyone can develop this disease.

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.

LDDs 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 LDD may include:

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

Risk factors

LDD is linked to a genetic mutation of the phosphatase and tensin homolog (PTEN) gene, which is a type of tumour suppressor gene.

Symptoms

In general, 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 vision.
  • Diplopia.
  • Nausea and/or vomiting.
  • General feeling of weakness.
  • Behavioural changes.
  • Difficulties with moving and/or talking.
  • Lethargy.
  • 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 LDD, 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.
    • PET (positron emission tomography) scan.
  • Blood tests.
  • Biopsy.

References

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