Types of Tumours

The information provided on this website is from current medical information available. Research and treatment processes are constantly evolving however and you should discuss with your doctor to receive advice on the most current treatments available.

The diagnosis of cancer in a child is without doubt one of the most distressing things that can happen to a family. Parents are given a lot of information to digest and have to make fairly rapid decisions due to often life threatening situations. It is important to take each day as it comes in the beginning. Learning about cancer and brain tumours in particular will give you some sense of control over a very stressful situation but it is also important to do this when you are ready and to do it slowly at a pace that allows you to absorb the complexity of the information. With the steady improvement in research and treatment we are also seeing an improvement in outcomes for children with brain and spinal tumours. We encourage every family to maintain hope and a positive attitude.

Childhood Cancer—Information

The most common childhood cancers are as follows:

Childhood Cancer Rates

Can we treat and cure children with cancer?

Children may have one of more than 100 different types of cancer. While leukaemia is the most common diagnosis at 32%, brain and spinal tumours are the most common solid tumour/cancer, with 25% of cases. We have seen a steady increase in survival rates for children with cancer over the last few decades. This does vary with the type and location of the cancer. Recent figures show us that over 70% of all children with cancer of the brain or spinal cord are successfully treated (Childhood Cancer Survival Rates in Australia 1995 -2004; Australian Paediatric Cancer Registry- published Oct 2010). This data is comparable to outcomes achieved in both the United Kingdom and Unites States of America.

How many children are affected by brain and spinal tumours in Australia each year?

In Australia there are approximately 200 new diagnoses of brain and spinal tumours each year.

To understand how brain tumours may affect children it helps to understand a little about the brain and how it develops normally.

The brain is part of the central nervous system and is important for every activity. It controls the things our body does normally, like our breathing, heartbeat and digesting food and the things we choose to do like talking and walking.

The brain is also involved with our senses (hearing, seeing, smelling, touching) as well as our thoughts, emotions, learning and memory. Finally it is the centre for our hormonal control which balances our stress responses, our metabolism, our thirst and water balance, and our growth and fertility.

The brain is protected by the bones of the skull and three thin membranes called meninges. Underneath this is a soft spongy mass of supportive tissue and nerve cells. The brain is cushioned and protected by cerebrospinal fluid (CSF) that flows through the hollow spaces of the brain, between the meninges and the ventricles. The CSF also travels down to surround the spinal cord. Blockage of any of these ventricles may cause a build up of fluid that result in hydrocephalus.

The brain has three major parts: the cerebrum, the cerebellum and the brainstem. The parts work together but also have special functions. Deep in the middle of the brain is a tiny but vital core, the pituitary gland and hypothalamus.

The upper part of the brain is called the cerebrum. It has two halves called the left and right cerebral hemispheres. The function of the cerebrum is to use information from our senses to tell us what is happening around us and how our body should respond. It also controls our emotions, our speech, thinking, learning and movement. The left hemisphere controls muscles on the right side of the body and the right hemisphere controls the muscles on the left side of the body. In 90% of people the left hemisphere controls speech and language. Right at the back of both hemispheres is an area that processes visual information from our eyes.

Underneath the cerebrum at the back of our brain lies the cerebellum. It controls our balance and co-ordinates complex actions like walking and talking.

In the middle of the brain, the hypothalamus regulates hunger, thirst, sleep and body temperature. This tiny structure also controls hormonal secretions from the pituitary gland. The pituitary gland is about the size of a pea and controls many vital functions.

The brain and spinal cord connect at the brainstem and it is here where control of our most basic functions such as breathing, heart rate and blood pressure occur.

The spinal cord is part of the central nervous system and made up of bundles of nerve fibres. The bones of the spine form a protection for the spinal cord and like the brain, spinal fluid and meninges also cushion it. The spinal nerves connect the brain with most parts of the body. Other nerves go directly to the eyes and ears and other parts of the head. The nerves are the networkthat carry messages back and forth between the brain and the rest of the body.

Brain Tumours

While most cells grow and divide in an orderly way sometimes cells lose their ability to control their duplication and this excess growth forms a mass of tissue called a tumour.

Tumours in the brain may be benign or malignant. Benign tumours grow slowly and tend to have clear borders. While they do not tend to invade nearby tissue they can press on sensitive areas of the brain and cause symptoms. Malignant tumours often grow rapidly and can invade tissue around them. This invasion may interfere with vital functions. Both tumours may be life threatening on presentation however malignant tumours will require further treatment after surgery.

Why do brain tumours form?

The causes of brain tumours are unknown. We do not know why one person develops a tumour and another doesn’t. We do know though that no one can “catch” a brain tumour from someone else. There also no evidence that head injuries can cause brain tumours in children. Researchers are studying families who may have more than one member with a tumour and are also looking at the impact of certain viral infections however in most cases we do not know why. There is nothing that parents could have done to prevent the tumour from occurring.

Where do brain tumours occur?

Tumours may occur throughout the brain and spinal cord.

What symptoms may occur?

While symptoms will depend on the location of the brain tumour the following may occur.

  • Headaches
  • Nausea
  • Vomiting — more noticeable in the early morning
  • Weakness of arms or legs
  • Seizures
  • Hormonal Abnormalities
  • Visual disturbances
  • Diabetes insipidus

How is a brain tumour diagnosed?

A complete and thorough neurological examination of the child is crucial in diagnosing a patient with a brain tumour. In addition medical imaging using magnetic resonance imaging, (MRI) ,now provide clear and accurate views of the brain and may reveal the presence of a tumour. CT scans may also be used to review the presence of hydrocephalus or a tumour. A lumbar puncture will reveal the presence of tumour cells within the CSF if a malignant tumour is suspected.

Treatment

A large team of health care professionals is involved in the decision as to how best to treat a child with a brain tumour. The different treatments depend on the tumour type, its location, whether it is benign or malignant and the age of the child. The team often includes a neurosurgeon, a paediatric oncologist, a radiation oncologist as well as nurses, a social worker, occupational therapist, physiotherapist, a dietician, speech therapist, and neuropsychologist. Other medical teams may also be involved if hormonal concerns or seizures are present.

  1. Surgery is used wherever possible to remove the entire tumour. If the tumour cannot be removed without damaging critical brain tissue then as much as possible is removed to remove pressure symptoms and radiotherapy or chemotherapy may also be added to the treatment regime. There may also be a requirement for a Ventriculo-Peritoneal (VP) Shunt if there is hydrocephalus present. Some tumours are unable to be removed and a small biopsy of the tissue is taken to assist the neuropathologist to identify the type of cells within the tumour. Some tumours are identified by special blood and spinal fluid tests along with the scans already taken and treatment does not require initial surgery. Sometimes too, MRI imaging may be sufficient to establish how best to treat that tumour.
  2. Chemotherapy is the use of drugs to kill cancer cells. The drugs may be given by mouth but are normally given by injection into the bloodstream (intravenous). The treatment is given in cycles to allow recovery prior to the next cycle. Some treatment is given as an inpatient in hospital and some may be given as an outpatient. The type of treatment depends on the type of tumour and usually lasts 8–12 months.
  3. Radiotherapy involves high-powered rays which kill quickly dividing cancer cells and prevent their spread. It may also be used to relieve symptoms when surgery is not possible. Radiotherapy is not painful and may be delivered for a few minutes every day for a number of weeks. Younger children may find it hard to lie still during treatment and a short daily anaesthetic will be used.
  4. Follow-up after treatment is ongoing for many years and may involve reviews by a team of medical personnel including the Paediatric Oncologist, Neurosurgeon, Ophthalmologist , Neurologist, Endocrinologist and Neuropsychologist. Assessments may include an MRI, lumbar puncture, blood tests, hearing tests and others as required. It is an important part of monitoring both the treatment outcome and the child’s progress as they return to the community.

What brain tumours are more common in children?

While this section provides the name of many different tumours the list is not exhaustive and some rare brain tumours may not be listed. More the 60% of childhood tumours are located in the back compartment of the brain which includes the cerebellum, the brain stem and the fourth ventricle. The remaining 30 – 40% occurs in one of the two cerebral hemispheres of the cerebrum or in the spinal cord.

Astroblastoma

These tumours arise from star shaped neural glial cells called astrocyte. Sometimes the terms “astrocytoma” and “glioma” are used interchangeably. The World Health Organisation classifies these tumours from grade 1 through to grade 4. Grade 1 is given to the most benign tumours and grade 4 to the most malignant. Common sites in children include the cerebrum, the cerebellum and the brainstem. Low-grade astrocytomas are usually localized and grow slowly over a long period of time. High-grade tumours are much more aggressive and require very intensive therapy.

Astrocytoma (also called Glioma)

These tumours arise from star shaped neural glial cells called astrocyte. Sometimes the terms “astrocytoma” and “glioma” are used interchangeably. The World Health Organisation classifies these tumours from grade 1 through to grade 4. Grade 1 is given to the most benign tumours and grade 4 to the most malignant. Common sites in children include the cerebrum, the cerebellum and the brainstem. Low-grade astrocytomas are usually localized and grow slowly over a long period of time. High-grade tumours are much more aggressive and require very intensive therapy.

In children, more than 80 percent of astrocytomas are low-grade; nearly 20 percent are high-grade (Glioblastoma Multiforme).

Atypical Teratoid/Rhabdoid Tumour (ATRT)

This malignant embryonal tumour most commonly occurs in children under two years of age and accounts for approximately 2% of childhood brain tumours. Intensive treatment is required and the prognosis is poor. If the tumour is found in older children there is often a better outcome.

Brainstem Gliomas

The brainstem is located deep within the posterior part of the brain and it is here where control of our most basic functions such as breathing, heart rate and blood pressure occur. Approximately 10% to 15% of childhood brain tumours are brainstem gliomas. Their location may cause sudden dramatic symptoms such as double vision, difficulty swallowing, clumsiness and weakness. The peak age group is between five and ten years.

Those tumours localised in the midbrain/medulla have a better survival than diffuse pontine gliomas. Because of their location surgery is not an option. Patients' symptoms often improve during or after six weeks of irradiation. Unfortunately, problems usually recur after six to nine months, and progress rapidly. Survival past 12 to 14 months is uncommon, and new approaches to treating these tumours are urgently needed.

Choroid Plexus Tumour

The choroid plexus is involved in the production of CSF and tumours arising from this location may cause marked hydrocephalus. Two types of choroid plexus tumours include the choroid plexus papilloma or carcinoma.

The choroid plexus papilloma is slow growing and tend to occur in children less the two years of age and account for 2–5% of brain tumours in children. Following complete resection of the tumour no further treatment may be necessary.

The choroid plexus carcinoma is a rare tumour and aggressive accounting for 10% of all choroid plexus tumours. Intensive treatment is required however.

Craniopharyngioma

This slow growing tumour accounts for 5–10% of childhood brain tumours and usually occur in children between five and ten years of age. Craniopharyngiomas result from the growth of cells that early in foetal development have failed to migrate to their usual area just below the back of the skull. These tumours arise from cells along the pituitary stalk and may grow up and involve the hypothalamus, optic nerve pathways and the third ventricle.

At diagnosis children may have symptoms such as headache and vomiting, hormonal deficiencies (growth delay, thyroid deficiencies, delayed puberty), visual disturbances and weight gain due to hormonal disturbances.

Complete removal of this tumour is optimal if it is in a favourable location. Outcome is good, however all of these children will require long term follow-up with a team of specialists to monitor possible hormonal and visual problems.

Ependymoma

This tumour accounts for up to 10% of childhood tumours and tends to occur before the age of five years. Ependymomas arise from cells lining the passageways in the brain that produce and store the cerebrospinal fluid or CSF. The tumours are most often in the back of the brain in an area called the posterior fossa. Very few ependymomas spread to other parts of the brain or to the spinal cord before they are diagnosed. Symptoms from these tumours often include headache nausea, vomiting, visual changes and balance problems.

Surgery is utilised to remove as much of the tumour as possible depending on the tumour location. The best survival rates are from those children who have had gross total resection of their tumour. Radiation oncologists are now using focal radiation techniques after surgery with excellent long term results. Chemotherapy has also been added to recent studies.

Gangliogliomas

These rare and benign tumours are slow growing but may occur anywhere in the brain or spinal cord. They arise from ganglia type cells, which are a group of nerve cells. The tumour represents about 4% of all childhood brain tumours.

Surgery is the major form of treatment if the location allows for complete removal. Radiotherapy or chemotherapy may be considered if this is not achieved. Outcome of this treatment is considered to be good.

Germ Cell Tumours

Germ Cell tumours may arise anywhere in the body however these tumours that arise from the germ cells in the brain, are most commonly found in the pineal or suprasellar region above the pituitary gland. Symptoms can include hydrocephalus headache and nausea. The optic pathways may also be involved and result in double vision. Germ cells also have the ability to spread to other parts of the brain. This tumour represents about 4% of all childhood brain tumours.

Germinomas are the most common of all germ cell tumours and have a peak incidence around ten to twelve years of age with boys being affected more than girls. These tumours respond favourably to radiation therapy and chemotherapy following surgery.

Non-Germinatous Germ Cell Tumours contain a mixture of malignant cells that secrete hormones. Treatment is similar and recent studies have shown marked improvement in outcome although data available is limited to 2 years post treatment.

Medulloblastomas (PNETs)

These are the most common malignant childhood brain tumour occurring in 20% of children. They most often occur in the first decade of life; half occur in children younger than five to six years of age.

These tumours tend to arise in the middle of the cerebellum, interfering with CSF flow and resulting in hydrocephalus. These tumours are also referred to as primitive neuroectodermal tumour (PNET). Tumours that have the same characteristics can also arise in other parts of the brain. This tumour type has a tendency to spread to other areas of the brain and spinal cord.

Treatment with skilled neurosurgeons, aims for complete resection followed by central nervous system radiation therapy and chemotherapy. Outcome of this treatment is considered to be good.

Optic Pathway Gliomas

This is a low grade tumour which grows along the optic nerve, optic chiasm and the hypothalamus. It is often a pilocytic astrocytoma and is called an optic pathway glioma because of its location. This tumour represents about 5% of all childhood brain tumours. 50%–70% of these children have an association with neurofibromatosis Type 1. This is a genetic disorder of the nervous system causing tumours to grow on nerves.

Signs and symptoms depend on the specific location of the tumour and the age of the patient. Decreased vision and double vision may be present. Infants may display head bobbing, head tilt, and nystagmus (oscillation of the eyeballs.) Growth and endocrine disturbances can also be symptoms of optic pathway tumours including changes in sleep and appetite.

Treatment strategies include surgery, chemotherapy and radiotherapy. The location of the tumour, the age of the child and the amount of visual loss will impact on the plan. Outcome of treatment is considered to be good.