Understanding Your Child’s Diagnosis
Doctors may talk about tumour type, grade, spread and molecular testing. Find clear explanations of how diagnoses are made, why results can take time and how to make sense of early information without jumping ahead or assuming outcomes.
After the initial shock of diagnosis, many parents want to understand what doctors are actually describing when they talk about their child’s tumour. The language can feel technical, uncertain or even contradictory at times.
Understanding a diagnosis is not about predicting the future. It is about learning how doctors describe the tumour, what information they use to guide decisions and why some answers take time to become clearer.
What Doctors Mean by “Diagnosis”
When doctors talk about a diagnosis, they are describing what the tumour is, not what will happen next.
A diagnosis is based on several pieces of information, including how tumour cells look under a microscope, where the tumour is located and, increasingly, the tumour’s molecular features. As new information becomes available, the diagnosis may be refined or updated. This does not mean earlier information was wrong. It reflects a growing understanding of the tumour.
Diagnosis helps guide treatment planning, but it does not determine outcome on its own.
Tumour Type, Grade and Location
You will often hear three key terms used together when a diagnosis is discussed:
Tumour Type
Tumour type refers to the specific kind of brain tumour a person has, based on the cells the tumour developed from and its molecular features. Different tumour types can behave very differently, which is why identifying the exact type helps doctors understand how the tumour is likely to grow and which treatments may be most effective.
Grade
Describes how abnormal the tumour cells look under a microscope and how quickly the tumour is likely to grow. Lower-grade tumours tend to grow more slowly. Higher-grade tumours tend to grow more quickly and usually require more intensive treatment. Grade gives doctors information about behaviour, not certainty about outcome.
Location
Location refers to where the tumour sits in the brain or spinal cord. Location of the tumour matters because it can affect symptoms, what treatment is possible and what side effects may occur. Two tumours of the same type and grade can behave very differently depending on where they are located.
Brain Tumours in Children
Brain tumours in children are different from those in adults. They tend to occur in different parts of the brain, behave differently and respond differently to treatment. There are many recognised types of childhood brain tumour, and doctors use information from surgery or biopsy to identify the type and guide treatment planning.
Brain tumours in children are different from those in adults. They tend to occur in different parts of the brain, behave differently and respond differently to treatment. There are many recognised types of childhood brain tumour, and doctors use information from surgery or biopsy to identify the type and guide treatment planning.
Common Types of Childhood Brain Tumours
Low-grade gliomas (including pilocytic astrocytoma)
Low-grade gliomas are the most common brain tumours in children. They tend to grow slowly and often behave less aggressively than higher-grade tumours.
When a tumour can be safely removed with surgery, treatment may focus on monitoring over time. When complete removal is not possible, for example if the tumour is close to critical brain structures, other treatments such as chemotherapy may be used to manage growth. Ongoing follow-up is usually required.
Medulloblastoma
Medulloblastoma is a malignant brain tumour that develops in the cerebellum at the back of the brain.
Treatment usually involves surgery followed by radiation therapy and chemotherapy. Medulloblastoma includes several biological subtypes, which can behave differently and respond differently to treatment. These features influence treatment planning and follow-up, and your child’s medical team will explain how this applies to your child.
Ependymoma
Ependymomas arise from cells lining the fluid-filled spaces in the brain and spinal cord and are more common in young children.
Treatment usually involves surgery and often radiation therapy. The extent to which the tumour can be safely removed during surgery is an important consideration in planning further care. Outcomes vary, and your child’s medical team will discuss what this means in your child’s situation.
High-grade gliomas (including glioblastoma)
High-grade gliomas tend to grow more quickly and can be challenging to treat.
Treatment often involves surgery where possible, followed by radiation therapy and chemotherapy. These tumours can behave aggressively, and treatment planning focuses on balancing tumour control with quality of life. Research and clinical trials continue to explore new approaches, and your child’s team will talk through what options are available and appropriate.
Diffuse midline glioma (including DIPG)
Diffuse midline gliomas grow in very delicate areas of the brain, such as the brainstem, which controls vital functions including breathing and heart rate.
Because of their location, surgery is not possible. Treatment may include radiation therapy to help manage tumour growth and symptoms. Care focuses on supporting the child and family, and specialist teams are involved throughout.
Atypical teratoid rhabdoid tumour (ATRT)
ATRT is a rare and aggressive tumour that most often occurs in very young children.
Treatment is intensive and usually involves a combination of surgery, chemotherapy and sometimes radiation therapy.
Treatment approaches continue to evolve, and care planning is tailored to the child’s age, tumour features and overall health. Children and families are supported closely throughout treatment and follow-up.
This is not a complete list of childhood brain tumours. Your child’s medical team will explain the specific type your child has, what it means and how it influences treatment planning.
Why Results Take Time
After surgery or biopsy, tumour tissue is examined by a pathologist. Additional testing, including molecular analysis, is often needed to understand the tumour more precisely. This process often takes around 1-2 weeks, and sometimes longer when additional testing is needed.
In some cases, early results are updated once further testing is completed. This information helps the team confirm the diagnosis and plan treatment.
Molecular Testing and Precision Medicine
In addition to standard pathology, your child’s team may recommend molecular testing. This involves analysing the genetic and molecular features of the tumour cells.
Molecular testing can provide additional information that influences care planning. This information can:
- provide a more precise diagnosis
- help predict how the tumour may behave
- identify whether targeted treatments or clinical trials may be suitable
- indicate whether further genetic review is recommended
This testing often takes longer than standard pathology and may not always identify a clear treatment target. When it does, the results can help refine treatment planning.
In Australia, this type of testing is often carried out through a national program.
The Zero Childhood Cancer (ZERO) program is a national Australian initiative that offers comprehensive genomic testing for many children diagnosed with cancer. It involves children’s hospitals across the country and looks in detail at each child’s tumour to identify genetic changes that may help guide treatment or clinical trial options.
Participation in the ZERO program is coordinated by your child’s treating team. Your child’s oncologist will explain whether it is appropriate in your child’s situation and what information it may provide.
Not every child will have a clear treatment target identified through genomic testing. For some families, the results help refine treatment planning or inform discussions about clinical trials. For others, the testing may confirm that current standard treatments remain the best option.
Diagnosis and Prognosis: What’s the Difference?
Diagnosis describes what the tumour is.
Prognosis describes how the disease is expected to behave over time and how it may respond to treatment.
Prognosis is based on information from many children with similar tumours, not on what will happen to one specific child. It is influenced by multiple factors, including tumour type, grade, location, whether it has spread, how much can be removed surgically and the tumour’s molecular features.
Because treatments continue to improve, published statistics may not reflect current outcomes. Your child’s medical team will explain what information is most relevant to your child’s situation.
How Doctors Talk About Risk and Outcomes
Doctors often use language that reflects probability rather than certainty. Words such as “likely”, “responding”, “aggressive” or “favourable” describe patterns seen across groups of patients. They are not predictions about an individual child.
When doctors talk about treatment “success”, they may be referring to different goals, such as curing the tumour, controlling growth over time or reducing symptoms and improving quality of life.
If any language feels unclear, it is appropriate to ask what it means in practical terms for your child.
Questions That Can Help Clarify a Diagnosis
You do not need to ask all questions at once. Some parents find it helpful to return to these questions over time.
- What type of brain tumour does my child have?
- What grade is it, and what does that tell us?
- Where is the tumour located?
- Has it spread, or is there concern about spread?
- Will molecular testing be done, and what might it tell us?
- Will my child’s case be discussed at a multidisciplinary team meeting?
- How might this diagnosis affect treatment planning?
- How will new information be shared as it becomes available?
Writing questions down and asking for explanations to be repeated is reasonable and expected.