Dialog Box

Children's Tumour Foundation of Australia



The information provided is not meant to replace the advice from your medical team, nor is it a complete list of terms, but will hopefully help you to understand more of the technical terms. More terms and definitions will be added to the page on an ongoing basis, so if there is a term you want clarity on, but can't find here, please drop us an email on support@ctf.org.au

Acoustic Neuroma

Is another term for a vestibular schwannoma, a tumour that can form on the nerve that takes sound and balance information to the brain (the 8th cranial nerve).


A test available during mid-pregnancy to look for genetic changes in an unborn baby. This is done by inserting a hollow needle into the uterus to retrieve a small sample of amniotic fluid (the fluid around the baby). As this fluid contains some of the baby’s cells it can then be sent to the lab to test for these genetic changes like Neurofibromatosis and other abnormalities. It is performed between 18 – 20 weeks into the pregnancy.


A drug or chemical that works to stop the effects of allergies.

Artery Stenosis

A narrowing of the arteries. In NF1 this can relate to arteries in the brain, kidneys or elsewhere.


Are a type of tumour found in the brain and/or spinal cord, and depending on where the astrocytoma is found, the symptoms can be quite different. Some are not detected and are indolent. This means they do not cause any symptoms or pain. For tumours in the brain, dizziness, seizures and changes in behavior may be the warning signs. If the tumours are in the spinal cord, then pain and weakness are usually the first things noticed. An MRI will be performed to properly diagnose whether a tumour is present. (see also ependymoma).

Auditory Brainstem Implant (ABI)

A device that aids in providing a sense of sound when the hearing nerve is no longer working. It does this by bypassing the cochlea and hearing nerves

Autosomal Dominant

Is the term used to describe the inheritance pattern of NF and other genetic conditions where a single faulty gene from one parent causes the condition. This happens even when the same gene from the other parent is normal. Therefore, the faulty gene dominates.

Autosomal refers to the fact that the gene change is found on a chromosome that is not a sex chromosome.


This is a drug that works to starve (anti-angiogenic) tumours by preventing the growth of blood vessels. It prevents growth of new blood vessels which in turn prevents the tumour from getting essential nutrients and oxygen.

Café Au Lait Marks (CALM)

Are flat, light brown (coffee coloured – hence the name) spots that can appear on the skin throughout life. Café au lait spots are found on just about everyone with NF1. These are harmless but are used as a diagnostic criteria for NF1.


Doctors who specialise in conditions of the heart and blood vessels.


A person who has a fault in one of the two copies of a given gene.  This generally applies to conditions where two faulty copies of the gene are required to have the condition e.g. Cystic Fibrosis. 

Chorionic Villus Sampling (CVS)

A test available at the end of the first trimester of pregnancy which tests the baby for biochemical or genetic abnormalities through sampling of cells (chorionic villi) from the placenta. As the placenta is made of the same cells as the baby it means the baby can be tested through taking a small sample of these cells for examination in the laboratory. The sample is taken using a slender needle through the cervix or abdomen guided by ultrasound. It is usually available between 11 and 14 weeks of pregnancy.

Chronic Disease Management Plan

A plan of action agreed upon with a General Practitioner with regards to a chronic disease/condition which identifies healthcare issues and needs and sets out the services to be provided by your GP and those you will take yourself. This can be complemented by a Team Care Arrangement in which at least two other health professionals can be nominated as assisting in providing care. Having A CDMP and TCAs in place can allow for Medicare rebates on specific allied health services in some instances where they are needed to address the chronic or terminal medication condition for which they were put in place.

Cognitive Assessments

A battery of tests often referred to as intelligence testing, learning assessment or neuropsychology assessment. They are used to determine an individual’s general thinking, reasoning, memory and other cognitive (thinking) skills. They are designed to test a person or child’s behaviour and learning capacity.

Cranial Nerve

The cranial nerves are a group of 12 nerves that originate in the brain that allows us to sense, feel or move.


Also referred to as cryotherapy involves the use of extreme cold from liquid nitrogen or argon gas to destroy abnormal tissue.

Computerised Therapy (CT) Scans

CT stands for Computerised Tomography and is used to scan the body. CT scans use X-rays and digital computer technology to create detailed three-dimensional pictures. Multiple X-ray projections are taken in thin cross-sections along the person’s body and are then combined to form an image.

Cyber Knife Radiosurgery

A non-invasive treatment using radiation for cancerous and non-cancerous tumours around the body. Usually used where surgery is not an option.


A specialist doctor with expertise and interest in medical conditions of the skin.

Early Childhood Early Intervention (ECEI)

A program of support offered by the NDIS specifically to assist children under the age of 7 years who have a developmental delay or disability.


The drying up of abnormal tissue using electric current delivered through a needle.

Emollient Cream

A cream (or ointment) that is used to soften and moisturise dry, rough and scaly and itchy skin. Some products act as a barrier to protect the skin from irritants e.g. water.


Doctors who specialise in treating conditions caused by hormones.

Ependymal Cells

Are a type of neural support cell. They are found in the brain and along the spinal cord. They also surround the blood vessels that support the two largest cavities (ventricles) in the cerebral hemisphere of the brain.


Ependymoma is a tumour arising from the cells that line the brain and spinal cord. These tumours generally occur in people with NF2 but it is quite rare (see also astrocytoma).

Essential Hypertension

High blood pressure that has no known secondary cause. Some healthcare professionals may refer to this as primary hypertension.


Freckling (aka Skinfold Freckling) is the term used to describe a cluster of small, brown freckles. These are usually found in the groin or under the armpit and like café au lait spots, they are harmless, but help doctors diagnose NF1.


An oral medication that is taken to treat seizures but can also act as pain relief for pain caused by damage to nerves. It acts upon the chemicals associated with the nerves and may be taken in conjunction with other medications when used to treat seizures.

Gamma Knife Radiosurgery

Gamma Knife Radiosurgery is a form of stereotactic radio-surgery that uses computer planning software to treat brain tumours with radiation therapy. It delivers 192 cobalt sources of intense radiation which all converge onto the precise location of the tumour without impacting the surrounding tissue. A frame is fixed to the patient’s head to ensure stability and pinpoint accuracy. Patients can be treated in a single day and it reduce the need for invasive surgery.Gastrointestinal Stromal Tumours (GIST)

Gastrosintestinal Stromal Tumour (GIST)

A type of tumour that develops in the gastrointestinal tract, a part of the digestive system, commonly the stomach and/or small intestine. These tumours arise in NF1 in a different way that they do for people who have one of these without NF1 as an underlying condition, and can appear as a single tumour or multiple.


Doctors who specialise in diagnosing and sometimes managing genetic/heritable conditions

Genetic Counsellors

Health professionals with specialised training in medical genetics and counselling.

Glial Cells

Support the nerves in our bodies. They are a lot smaller than the neurons they support, and are at least three times more numerous than neurons in the body. The have a number of functions including physical support of the brain, helping with developing the nervous system, maintaining and insulating neurons, and providing metabolic function for neurons. There are several types of glial cells including: astrocytes, ependymal cells, microglia, satellite cells, oligodentrocytes, and Schwann cells, some of which are often involved in NF tumours.


Hamartomas are small benign lumps which are caused by an overgrowth of multiple localised cells. They are generally slow-growing and self-limiting and are usually associated with an underlying genetic condition rather than a single mutation in a cell.

Juvenile Cataracts (Posterior Subcapsular Opacities)

A cloudy covering over the capsule that holds the lens of the eye, which stops light from entering the retina at the back of the eye.  

Juvenile Myeloid Leukaemia

A rare childhood cancer which occurs when the body makes too many while blood cells. Which pack the normal cells in bone marrow, blood and other areas of the body causing symptoms. Having Neurofibromatosis type 1 can make it more likely for a child to develop this condition. Symptoms include joint pain, fatigue, anaemia, easily bruising. Children with NF1 who develop juvenile xanthogranulomas (JXG) are more prone to JMML that other children with NF1.  

Juvenile Xanthogranulomas (JXG)

Xanthogranulomas are small, flat yellow or red lesions that appear on the skin. They are often only 1-2cm is diameter and often appear on the arms, chest and head of children. They generally disappear on their own and are not found after early childhood. 

Lisch Nodules

Lisch nodules or hamartomas are small, dome-shaped lumps that form on the surface of the eye. They are common in people with a diagnosis of NF1. 

Lisch nodules are usually brown in colour and appear when a child is around 5 years of age. They are found on the iris (the coloured part of the eye) but do not interfere with vision in any way and are harmless. Lisch nodules are only diagnosed by an ophthalmologist using a special slit lamp but do not require any treatment. They are helpful in the diagnosis of NF1 and they do not occur in people with a diagnosis of NF2. 


A “big” head. This describes the condition where a child’s head circumference (the measurement around the widest part of the head) is greater than the 98th percentile.  

Magnetic Resonance Imaging (MRI)

A scan used to take high resolution pictures inside the body. It uses a magnetic field and radio waves to take images of soft tissue such as organs, tissues and muscles that don’t show up on x-rays. MRI scans are costly and are only recommended when there is a clinical reason and are not used for routinely examining people with NF. As many as 60% of children and adolescents can have UBOs found on MRI scans, although these usually disappear during adulthood. UBO’s are Unidentified Bright Objects which are areas of signal hyperintensity seen on the scan. No one really understands these bright spots yet, but researchers do not think they are linked to NF severity, learning difficulties or cancerous tumours.  

Malignant Peripheral Nerve Sheath Tumour (MPNST)

Are aggressive cancers that generally originate in a plexiform neurofibroma. They occur in 5-10% of people with NF1 (often when a person is in their 20-30s) but are rare in the general population. If a plexiform neurofibroma grows rapidly, changes form or becomes painful or hard, it should be investigated as soon as possible. Usually a biopsy will be performed followed by surgery. These tumours can spread quickly so prompt treatment is essential.  


An X-ray of breast tissue used to detect changes that are too small yet to be detected by physical examination.They can be done to screen for breast cancer in women who have no signs or symptoms or to diagnose breast cancer in women who have discovered a lump or present with other symptoms. 

Mast Cell

A connective tissue cell which is known to release histamine and other inflammatory-related substances.

MEK Inhibitor

A drug/chemical that helps flick the off switch on a pathway that controls cell multiplication. When someone has a faulty NF1 gene the pathway is always switched on allowing uncontrollable cell growth. A MEK inhibitor attaches itself to the protein MEK1 or MEK2 which sit along this pathway, and force them to turn off therefore stopping cell multiplication. 


A type of tumour that develops on the membrane that surrounds the brain. 

Myelin Sheath

A protective layer around the nerves that is made up of fat and protein that works as insulation to allow the electrical impulses to travel efficiently along the nerves. 

National Disability Insurance Scheme (NDIS)

A government initiative to provide support services and equipment to eligible Australians living with significant or permanent disability. The aim of the scheme is to build skills to assist everyday function.  


Neurofibromas are benign tumours found on or within the body. All Neurofibromas grow from the tissue surrounding a nerve fiber. Neurofibromas generally appear in late childhood or early adolescence when hormones can affect the growth rate. They can be small, pea sized lumps or up to several centimeters in size. 

Cutaneous or Dermal Neurofibromas are found on or under the skin. They are slow growing, usually soft and malleable (moveable), and can look smooth or like a collection of bumps. 

Subcutaneous Neurofibromas are found deeper in the body and are firmer to the touch. Discrete neurofibromas are encapsulated, meaning they have definite edges or borders. Most people with NF1 have only several neurofibromas, but more rarely, some people can have hundreds or thousands of them, most commonly on the chest, arms and back. While they can be disfiguring if they appear on the face, neurofibromas are generally only removed it they cause concern or pain or are in an inconvenient location (e.g. under a bra strap). 

It is extraordinarily rare for a discrete neurofibroma to become cancerous. However, they may have a detrimental impact on body systems by pressing on bone, nerves or other tissue, but will not invade these other structures. On the other hand, plexiform neurofibromas can wrap themselves around blood vessels and nerves and can therefore be more difficult to treat. (see Plexiform neurofibroma)  

Neuroendocrine Tumours

A rare type of tumour that develops on neuroendocrine cells in the digestive or respiratory tracts, but can appear elsewhere. The cells in which they develop from produce hormones and small proteins that help the body function.


Specialist doctors with expertise and interest in conditions of the nervous system


Neurons are the name given to nerve cells.


Associated with nerves


Specialist doctors with expertise and interest in the surgical treatment and management of conditions of the brain, spine and nervous system.

Non-Steroidal Anti-Inflammatory Drugs

Commonly used to treat pain and inflammation from musculoskeletal issues. They work by blocking the chemical responsible for making a hormone that contributes to inflammation.

Examples of NSAIDs include: aspirin, ibuprofen (nurofen), diclofenac (voltarin). 


Doctors who specialise in the prevention, diagnosis and treatment of cancer.


Ophthalmologist is a doctor who specialises in vision and the eye. These doctors are trained to perform eye examinations, diagnose eye conditions, prescribe medications or otherwise treat them and to perform surgery on the eye.

Optic Nerve

Transmits information from a person’s eyes to their brain allowing them to see.

Optic Pathway Glioma (OPG)

Optic Pathway Glioma (OPG) is a tumour that can develop behind the eye. They occur in about 15% of children with NF1 and usually appear between the ages of 4 and 6. Tumours can start in the cells surrounding the Optic Nerve (which connects the eyeball to the visual cortex in the brain) or in the Optic Chiasm (where the two optic nerves cross). Most Optic Nerve Gliomas are slow growing and do not require treatment. Only 5% of children with NF1 will experience visual disturbances as a result of an OPG. 

Orthopaedic Surgeon

Doctors who specialise in management and surgical treatment of conditions and diseases of the bones


The extent to which a particular gene or set of genes is expressed in the phenotypes of individuals carrying it, measured by the proportion of carriers showing the characteristic phenotype.

Position Emission Tomography (PET) Scan

An imaging test that helps to determine how well your body’s tissues and organs are functioning. These are considered safe scans which expose you to a small amount of radiation, considered acceptable and are used to assess cancers, neurological and cardiovascular disease.


A tumour of the adrenal gland tissue. These adrenal glands are a triangular shaped gland one of which is found on top of each kidney and a responsible for producing hormones involving with controlling heart rate, blood pressure and metabolism. When a pheochromocytoma develops in one of these glands too much of these hormones is produced causing symptoms. They are rare, and not often cancerous.

Plastic Surgeon

Doctors who specialise in restoration, reconstruction or alteration of the human body.

Plexiform Neurofibromas 

Plexiform neurofibromas are large and diffuse benign tumours that generally occur deep within the body. They are estimated to occur in one third of people with NF1, although these can be asymptomatic in some people (they don’t know they have one as it does not cause any problems). 

Plexiform neurofibromas are usually congenital (meaning the person was almost certainly born with it). People with NF may have a darker or thicker patch of skin which is indicative of an underlying plexiform neurofibroma. Plexiform neurofibromas on the face are usually obvious in the first year of life. Others can grow throughout childhood, but new ones rarely form after puberty.  

Plexiform neurofibromas, unlike discrete neurofibromas, are large and can invade other structures like bones and organs. They often have their own blood supply which makes them difficult to excise surgically and are likely to regrow if they are removed. Less than 10% of Plexiform neurofibromas may become malignant (cancerous). If a plexiform neurofibroma become painful or hard it needs to be investigated promptly (see also MPST).  


 An oral medication taken to treat seizures and pain caused by damage to nerves. In the instances when it is used to treat seizures it is often prescribed along with other medications. 


The medical term for itch. General skin care and avoidance of perfumed soaps is recommended. 


Occurs when a long bone is broken but does not heal properly. This results in a “false” (pseudo) joint forming. It occurs in only 2% of NF1 children, usually occurs within the leg (tibia or fibia), but can also involve the arm bones. Pseudoarthroses rarely repair on their own and require surgery to correct. Surgery will aim to repair the old fracture,  stabilise the bones and reduce leg length discrepancies. Extreme cases can result in amputation of the limb to reduce pain and enhance quality of life for the patient.


Mental health professionals who take on various roles but who are interested in conditions of the mind.

Pulmonary Valve

A heart valve which lies between the right ventricle (cavity) of the heart and the pulmonary artery (the artery connecting to the lungs). 


A complex tumour arising from bone, cartilage, or soft tissue. Soft tissues sarcomas include Malignant Peripheral Nerve Sheath Tumours (MPNST) and Gastrointenstinal Stromal Tumours (GIST) which are seen in association with NF1.

Schwann Cells

These are a type of cell that coats (sheaths) the nerves in the peripheral nervous system (outside the brain and spine). They coat the axons and of motor and sensory neurons forming the myelin sheath.


A schwannoma is a benign tumour that arises from Schwann Cells. Schwann cells form myelin, which is the “insulation” around nerves. Schwannomas are characteristic of NF2 and Schwannomatosis.  Vestibular schwannomas often develop in late teens or early adulthood and occur on the 8th cranial nerve. This nerve is responsible for hearing and balance and as such, NF2 is often diagnosed after people experience dizziness, balance problems and hearing loss.  

Schwannomas can also occur on other cranial nerves. Schwannomas grow slowly on the outside of nerves but can press on nerves or push them onto other structures causing pain and neurological complications. Schwannomatosis refers to multiple schwannomas on peripheral nerves, which cause chronic pain.  


Scoliosis refers to a lateral (sideways) curvature of the spine, like an “S” shape. Severe curves can cause hips or shoulder bones to be different heights and therefore effect posture and balance. It is present in 10% of people with NF, but only less than 2% of the general population. A curve that is between 25-40 degrees is often treated with a special brace fitted by an orthopaedic specialist. Braces correct the bend in the spine but are hard, hot and uncomfortable and poorly tolerated by most people. Moderate cases of scoliosis may be treated with surgery where metal rods and wires correct the curve in the spine.  

Severe cases, (called Dystropic Scoliosis) is only found in people with NF1 and occurs between the ages of 6-10.  


Sometimes referred to as “fits” seizures are the uncoordinated and rapid electrical firing of the brain which causes a loss of consciousness or altered level of consciousness and sometimes a stiffening and then jerking of the limbs.

Short-Acting Opioids

These are used as pain relief, and generally take 20- 30 minutes to have an effect and the effect only lasts 3 – 4 hours. An opioid such as codeine may be the only pain relief in them or they may be combined with other pain relief medications such as ibuprofen (nurofen).


Strabismus is the medical term used to refer to “turned”, “lazy” or “crossed” eyes. Essentially this means that when looking at an object both eyes will point in different directions. While this is a common condition it can be associated with an underlying cause warranting further investigation in some cases.

Sphenoid Wing

One aspect of the sphenoid bone, a skull bone, centrally located behind the nose and eyes.

T2 Hyperintensities

Previously known as Unidentified Bright Objects (UBOs) these are lighter areas seen on the brain (or spine) in an MRI image. As these images are produced in black and white, they appear as areas of brightness on the scan image. These have been found to be benign and often disappear as a child grows.


A medical term used to describe ringing in the ears.

Trigeminal Nerve

Is the largest of the cranial nerves. It assists with the functions of chewing and clenching of the teeth, and provides sensation to muscles associated with the eardrum, and providing sensation to the face.


An ultrasound scan uses high frequency sound waves to create an image of internal bodily structures and is used to detect abnormalities in blood vessels and organs. It is generally painless and and non-invasive.


An organism that is used to carry genetic information, most often sequences generated in a lab setting, into an organism for study or treatment. Before use the "host"

Vestibular Schwannomas

Also known as an acoustic neuroma, is a tumour that can form on the nerve that takes sound and balance information to the brain (8th cranial nerve).


A picture of the inside of the body created by using small doses of radiation.