Dysembryoplastic neuroepithelial tumours (DNET or DNT) are a rare of central nervous system (CNS) tumoura tissue mass that forms from groups of unhealthy cells that generally develop within cortical grey matter, which are the outer most regions of the brain and spinal cord that contain a high concentration of nerve cellsthe basic structural and functional unit of all living things. DNETs are classified as glioneural tumours, as they contain both glial cells (supportive cells within the central nervous system) and nerve cells/neuronal cells (receive sensory input from internal and external stimuli, and relay information to the brain).
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 tissuea group of cells that work together to perform a function, 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 bloodthe red bodily fluid that transports oxygen and other nutrients around the body pressure).
DNETs are generally considered to be slow-growing and benignnot cancerous, can grow but will not spread to other body parts (non-cancerous) tumours. They most commonly develop in the grey matter of the cerebral cortex, however it can also develop in the basal ganglia (cluster of neurons beneath the cerebral cortex), brain stem, and cerebellum. DNETs that develop in the septum pellucidum (thin layer between the right and left hemispheres of the brain) are now classified separately, and are called myxoid glioneural tumours.
DNETs are slightly more common in males, and are generally diagnosed in people under the age of 20. However, anyone can develop this disease.
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 cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs 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, as most DNETs are considered benign, these tumours are generally considered low-grade and are not staged.
Once your tumour has been diagnosed, your doctor may 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 DNETs 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.
- 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.
Unfortunately, this type of cancer does not often respond to chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells and radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
Risk factors
Because of how rare DNETs are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease.
Symptoms
The main symptom of DNETs are focal seizures, which are a malfunction of nerve cells that result in intense, uncontrolled, and sudden surge of electrical impulses across the brain. In many cases, a patients first seizure will occur before the age of ten, and will occur without any other physical or neurological symptoms.. Seizures that are the result of a DNET are often resistant to anti-seizure medication.
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 DNET, 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.