Common Brain Tumours in Children – Cerebral Hemisphere
Some brain tumours occur within one of the two cerebral hemispheres or in the spinal cord.
Tumours of the hemispheres include astrocytomas, ependymomas, oligodendrogliomas, craniopharyngiomas, choroid plexus carcinomas, supratentorial PNETs, pineoblastomas, and germ cell tumours.
The most common tumours of the spinal cord are astrocytomas and ependymomas.
Please refer to the Brain Tumour Glossary for explanations of any terms that you do not understand.
If there are terms in this article that do not appear in the glossary, you can also make use of the NCI Dictionary of Cancer Terms (link on the right hand side of almost page every page if you ever need them again – look for Bennie Bookworm)
The brain is composed of neurons (nerve cells), nerve fibres, and glial cells (also known as neuroglia), which fill up the space between nerve cells and fibres.
Gliomas are a large family of tumours and make up around 30% of all paediatric tumours. Gliomas begin in glial cells, the supporting cells of the nervous system.
Gliomas invade the surrounding brain tissue as they grow; the border with healthy brain tissue becomes indistinguishable, making treatment very difficult.
Most tumors in the brain arise from glial cells. This group of tumours is known to include different types, ranging from relatively benign to extremely malignant. They can develop in any part of the brain.
Treatment and prognosis of the different types of Gliomas depends on their exact location and how quickly they are growing. Many of these types of tumours cause seizures.
Gliomas are categorised for where they are found and the type of cells from which the tumour originated.
The following are the different types of gliomas:
Astrocytomas are glial cell tumours that originate in the connective tissue cells called astrocytes, which can be found anywhere in the brain or spinal cord.
Astrocytomas are the most common type of childhood brain tumour and are normally classified as either high-grade or low-grade tumours; High-grade astrocytomas are the most malignant of all brain tumours.
Astrocytomas are further classified for presenting signs, symptoms, treatment, and prognosis, based on the location of the tumour.
The most common location in which these tumours occur is in the cerebellum, where they are called cerebellar astrocytomas. Those with astrocytomas usually present with symptoms of increased intracranial pressure, headaches, and vomiting. They can also experience double vision, problems with walking and impaired coordination.
Brain Stem Gliomas
Brain stem gliomas occur in the brainstem and cannot be surgically removed due to the remote location and the complex and delicate functions such as motor skills, sensory activity, coordination and walking, the beating of the heart, and breathing that are controlled by this part of the brain.
Brain stem gliomas occur almost exclusively in children; the group most often affected is the school-age child.
Symptoms that present with brain stem glioma generally do not include increased intracranial pressure, but may include problems with movement of the face or one side of the body, double vision, or difficulty with walking and coordination.
Brain stem glioma is most often diffused (spread freely) through the brain stem by the time of diagnosis. This type of tumor is typically very aggressive, meaning that it grows and spreads quickly.
Ependymomas can occur in any part of the brain or spine, but most commonly occur in the cerebrum, the largest part of the brain. Ependymoma start in the ependymal cells that line the ventricles (fluid-filled spaces) in the brain and the central canal of the spinal cord.
The brain and spinal column make up the central nervous system (CNS), where all vital functions are controlled, including thought, speech, and body strength.
The tumour often blocks the flow of the CSF (cerebral spinal fluid, which bathes the brain and spinal cord), causing increased intracranial pressure. This type of tumour mostly occurs in children younger than 10 years of age.
Ependymomas can be slow-growing, compared to other brain tumours, but may recur after treatment is completed. Recurrence of ependymomas results in a more invasive tumour which is more resistant to treatment.
Ependymoma is often classified based on its location and whether or not it has spread:
- Supratentorial: The tumor is above the membrane that covers the cerebellum, known as the tentorium cerebella.
- Infratentorial: The tumor is growing below the tentorium cerebella.
The tumor can also be described by its grade, which is a measure of how “wild” the cancer cell looks under a microscope. Lower grade tumors have more normal looking cells and typically have a better prognosis.
Children with ependymoma sometimes show no symptoms at all, but if they do, then headaches, seizures, nausea and vomiting, changes in vision such as blurriness, difficulty with walking or balance, swelling of the nerve at the back of the eye, jerky eye movements, or neck pain are common symptoms.
Optic Nerve Gliomas
Optic nerve gliomas are found specifically in the optic nerve, which is the part of the brain that connects the eye to the visual center of the brain and sends messages from the eyes to the brain. They make up about 5% of paediatric tumours
Optic nerve gliomas are frequently found in children with neurofibromatosis, a condition a child is sometimes born with that makes him/her more likely to develop tumours in the brain.
Optic nerve gliomas are usually slow-growing and can be treated successfully with surgery, radiation therapy, or chemotherapy. Because visual pathways and/or the hypothalamus are affected, children with these tumours often have vision and hormone problems due to the tumour’s location at the base of the brain where hormonal control is located.
Gliomas are divided into four stages according to how samples harvested during surgery appear under the microscope. These stages correlate strongly with treatment outcomes. The more advanced the stage, the worse the treatment outcome is likely to be.
The 5-year survival rate for patients at the most advanced stage is around 8%, making this one of the very worst cancers in terms of response to treatment.
Posted on 12 May, 2015, in Articles, Blog, Brain Cancer and tagged Astrocytomas, brain cancer, brain cancer awareness, brain cancers, brain tumours, Ependymoma, gliomas, Little Fighters Cancer Trust. Bookmark the permalink. 1 Comment.