Brain tumors, also called intracranial tumors, are abnormal growths of tissue in the brain. The tumor cells lack the mechanisms to control cell growth, leading to rapid cell division (1). Some brain tumors may be contained to where they originated (benign), while others can be cancerous, spreading to distant parts of the brain and the body. Treatments are planned based on nervous system damage since the brain is still developing in children.
The incidence of brain tumors in children ranges from 1.15 to 5.14 cases per 100,000 children. The highest incidence of pediatric brain tumors is reported in the US (2). Brain tumors are the most common types of tumor that affect children and adolescents and are the leading cause of cancer-related mortality and morbidity in children.
Read this post to know about the symptoms, causes, risk factors, types, diagnosis, treatments, and complications of brain tumors in children.
Symptoms Of Brain Tumors In Children
Brain tumor symptoms in children may vary depending on the location and size of the tumor. However, all the types of tumors that grow in any part of the brain can increase intracranial pressure in children.
Increased pressure on the brain may cause the following symptoms and complications (3):
- Personality changes
These symptoms of increased intracranial pressure are common in older children as they have well-formed skulls, limiting the space for the brain. In comparison, babies with growing brain tumors may not exhibit these symptoms since a baby’s skull is not fused, and it enlarges to accommodate the brain and the tumor. As a result, you may notice enlarged heads in babies with brain tumors.
1. Brain tumors in the cerebrum
The cerebrum is the front part of the brain and has right and left hemispheres. This part controls our movements, speech, emotions, and thoughts and processes the information received from the sense organs. Brain tumors in the cerebrum can cause the following symptoms.
- Vision problems
- Hearing problems
- Walking difficulties
- Mood changes such as depression
2. Brain tumors in the cerebellum
The cerebellum is located at the back of the brain, and it coordinates muscle movements. The cerebellum also helps in maintaining balance, posture, and equilibrium. Thus, tumors affecting the cerebellum may cause the following symptoms.
- Swallowing difficulties
- Walking difficulties
- Eye movement issues
- Speech impairment
- Clumsy movements of limbs and extremities
Most children with cerebellar tumors are affected by ataxia, a combination of disorders that affects coordination, speech, and balance and causes difficulties in walking, tremors, a decline of motor skills, and slurred speech (4).
3. Brain tumors in the brainstem
The brainstem is located at the base of the brain and includes the midbrain, medulla, and pons. This part of the brain controls the sensations and muscles, including those linked to breathing and heartbeats. In addition, many cranial nerves originate from the brainstem, and they carry messages to and from the brain to the upper part of the body, such as to the face and the area around the eyes. The brainstem is also connected to the spinal cord.
Tumors in the brainstem can cause the following symptoms.
- Ataxia or walking difficulties
- Swallowing difficulties
- Double vision
- Hearing impairment or loss
- Facial and eye movement issues
- Muscle stiffness
The symptoms may vary depending on the size and location of the tumor. If the tumor invades larger areas of the brain, more symptoms may be exhibited. Small tumors may cause one or two symptoms based on their location. These symptoms are also observed in other neurological disorders and health conditions, so it is recommended to seek medical consultation to identify the cause.
Causes Of Brain Tumors In Children
The exact cause of most brain tumors is unknown. However, research suggests that changes such as DNA mutation in healthy brain cells can result in tumors. DNA is the hereditary material that makes genes, which control cell growth and division. Oncogenes regulate the growth, division, and sustained life of cells, and tumor suppressor genes control cell division and death at the right time4 (5)
Thus, any DNA mutations affecting the turn-on of oncogenes or turn-off of tumor suppressor genes can result in uncontrolled cell growth. These changes can be inherited or acquired in childhood cancers.
Risk Factors For Brain Tumors In Children
A few risk factors have been identified for brain tumors in children. Among the possibilities are inherited syndromes, which can be a risk factor for inherited gene changes. The following gene changes may increase a child’s risk of developing specific brain tumors4 (5).
- Li-Fraumeni syndrome. This syndrome is associated with TP53 tumor suppressor gene changes. This gene typically prevents the growth of cells with DNA damage. Thus, these gene mutations may cause abnormal cell growth resulting in brain tumors such as gliomas.
- Tuberous sclerosis. This is a rare genetic disorder that causes tumors.
- Neurofibromatosis (NF). This is a genetic disorder that causes tumor growth along the nerves and skin pigmentation.
- Von Hippel-Lindau syndrome (VHL). This is a genetic disorder with an increased risk of growth and tumors in the body.
The causes and risk factors of brain tumors in children without inherited syndromes are often unknown. Exposure to carcinogenic (cancer-causing) chemicals, such as tobacco smoke or certain chemical substances through food or air, can increase the risk of cancers. However, the brain is usually protected from them.
Other than radiation exposure, lifestyle-related or environmental factors are not associated with pediatric brain tumors. Unfortunately, this indicates that the child or their parents cannot prevent childhood brain tumors in most cases.
Diagnosis Of Brain Tumors
In some cases, pediatric brain tumors can be preliminarily diagnosed by examining the child’s symptoms, health history, and neurologic tests, including muscle strength, reflexes, mouth and eye movements, and coordination. The pediatrician may refer suspected cases to specialists in neurology (neurologist or neurosurgeon) and cancer specialists (oncologists) for a detailed analysis.
The following tests may be ordered for diagnosing brain tumors in children (3).
- CT scan (computed tomography scan): It uses X-rays to create images of the brain. Skull bones are more evident on CT scans.
- Lumbar puncture (spinal tap): It involves collecting cerebrospinal fluid (CSF) with a special needle. The CSF analysis may display cancer cells (abnormal cells) and tumor biomarkers in some children.
- Blood tests: They may help identify specific tumor biomarkers that are released by the tumors to the bloodstream.
- MRI scan (magnetic resonance imaging scan): It uses magnetic fields to visualize the brain tissues. The images of cancers and other soft tissue of the brain are more precise in MRI scans.
- PET scan (positron emission tomography scan). It involves the injection of radioactive sugar into the bloodstream. Cancer cells absorb these sugars in higher quantities to meet their high energy demand, and the image shows the areas where the radioactive sugars are concentrated.
- Biopsy. These samples are collected during surgery or using a stereotactic needle if an operation cannot be performed. Lab testing of the sample can reveal the type of tumor and its characteristics, such as how fast it grows. Pathologists may determine the grade of the cancer cells during a lab analysis of the biopsy samples. This helps know the tumor’s speed of growth and appearance. For example, high-grade cancer cells grow rapidly.
These tests help determine the type of tumor, size, location, area of spread within and beyond the brain, and the possibility of surgical removal of the tumor. Doctors usually plan cancer treatment depending on the type of tumor, its characteristics, and stage after diagnostic evaluation.
Treatment For Brain Tumors In Children
A multidisciplinary team, including specialists, such as pediatricians, oncologists, neurologists, neurosurgeons, dieticians, and rehabilitation therapists, are involved in brain tumor treatment. These doctors determine a brain tumor treatment plan according to the tumor’s characteristics and individual factors.
The following treatments are recommended for brain tumors in children (6).
- Surgery: Most brain tumors in children are surgically removed. A biopsy is also done as a part of the Removal of tumors can reduce intracranial pressure, and it may be the only treatment required for slow-growing tumors (low-grade tumors) in children.
- Chemotherapy: This is recommended for high-grade tumors (aggressive tumors). Chemotherapeutic drugs can be injected into the vein (intravenous or IV) or given as oral pills. In some cases, chemotherapy drugs are directly injected into the cavity after surgical removal of the
- Radiation therapy: High-energy radiation beams are directed to the tumor and immediately adjacent tissues. This treatment is administered with caution to young children since their brains are still developing. Some tumors, such as medulloblastoma, may require radiation to the entire spinal cord and brain. This may also be given as adjuvant therapy with surgery to prevent recurrence and spread.
Although the side effects of these treatments may vary in each child, early diagnosis and treatment can improve the recovery and outcomes in children. Occupational, physical, and speech therapy can speed up recovery and improve outcomes. Regular follow-ups are recommended to identify neurological damages and side effects and resolve them as early as possible.
Possible Complications Of Brain Tumors
The complications of brain tumors may vary depending on the size and location of the tumor. Some children experience temporary deficits, such as weakness of muscles, after surgery, which may often resolve quickly. However, children with substantial, permanent brain damage before interventions may continue to experience issues even after tumor removal.
- Growth and developmental delay or abnormal growth
- Infection and bleeding after surgery or chemotherapy
- Learning disabilities
- General anesthesia-related problems after surgery
- Nervous system damages resulting in poor coordination and muscle strength
- Speech, hearing, and vision problems due to tumor
- New cancer growths (secondary tumors)
- Recurrence of the cancer
- Delayed or early puberty
- Infertility in future
- Hormonal deficiencies
- Emotional issues due to stress
Some of these complications may go unnoticed for many years after cancer treatment. Hence, regular follow-ups and detailed screenings are required to detect these issues early and address them with the help of pediatric neuro-oncology specialists.
Tips To Help Children With Brain Tumors
The following tips can help parents and children fight brain tumors (8).
- Stay with the child during the tests and treatment. Explain what is happening in a way they can understand depending on their age. This may help reduce the anxiety and stress of procedures done when they are awake.
- Observe your child’s symptoms and energy levels at home. Encourage them to rest well and participate in regular exercises or activities as recommended by the doctors.
- Maintain a daily record of sleep patterns, medicines, body temperature, and any side effects to inform the doctor during the visits.
- Follow a regular diet unless the doctor recommends specific foods or supplements. You may include more healthy food and encourage them to drink enough fluid regularly. Since children may lack appetite during chemotherapies, including their favorite foods in their diet can be helpful.
- Seek support from family, friends, support groups, and organizations. Parents of children with cancer also require constant encouragement and hope to stay positive during long-term care. You could ask your child’s doctor about local support groups.
- Check with the doctor before scheduled vaccinations or other treatments. Cancer treatment may affect the immune system functions; hence, the administration of some vaccinations may be delayed.
- Bring a favorite toy or storybook for younger children during clinic visits. This may keep them occupied while waiting in the clinic. Likewise, reading books, playing games, listening to music, or watching shows can help keep older children occupied while waiting.
- Take young children to the play areas in hospitals during their visits or in-hospital stays if allowed by the doctor. Doctors may also ask recreational therapists to visit children at their bedsides and encourage them to stay positive.
You could also explain your child’s condition to siblings, peers, and teachers to sensitize them about the struggles the child may be facing.
Prognosis And Survival Rate Of Children With Brain Tumors
The long-term survival rate and prognosis of children with brain tumors vary in each child depending on the child’s age and health as well as tumor type, size, location, and spread. Additionally, metastasis and response to treatments can also influence the outcome (9).
The five-year survival rate of children with both benign and malignant brain and spinal cord tumors is good. Three in four children with brain tumors survive for more than five years. The five-year survival rate is a general estimate, and the survival rate is gradually improving with advances in medical care (10).
Types Of Brain Tumors
More than 150 types of brain tumors have been documented, and they can be grouped into the following two categories (6).
1. Primary brain tumors
Primary brain tumors are abnormal growths originating from the brain tissue or the brain’s immediate surroundings (1). They can be further categorized into the following groups.
- They are tumors made of glial cells, which are supportive cells around the nerves that help them function.
- Non-gliomas. They are non-glial cell tumors that develop in brain structures such as glands, nerves, or blood vessels.
Primary brain tumors can also be classified based on their characteristics.
- Benign brain tumors are non-cancerous, slow-growing tumors. Thus, they may not spread to other areas of the body. However, they can grow in and near sensitive brain structures and limit treatment
- Malignant brain tumors are cancerous growths that can spread to other areas rapidly. They can invade nearby tissues and metastasize to distant areas of the brain and other organs or tissues.
2. Metastatic brain cancer
Metastatic brain cancers, also known as secondary brain tumors, comprise tumors that spread from other body parts to the brain (1). For example, melanoma (skin cancer) has a greater tendency to spread to the brain. Childhood leukemia can also spread to CSF, and it is treated as leukemia.
The common types of brain tumors in children include (11)
- Astrocytomas. They are the most common pediatric brain tumor, accounting for nearly half of all childhood brain tumor cases. These tumors originate from the astrocytes or astroglia, which are star-shaped glial cells. Pilocytic astrocytoma and glioblastoma multiforme are types of astrocytomas in children.
- Ependymomas. They are gliomas that line the ventricles of the brain, which are open areas where the CSF flows.
- Brain stem gliomas. They are usually located in the middle of the brainstem. The diffuse intrinsic pontine glioma (DIPG) is a rare, fast-growing type of brainstem glioma that cannot be removed surgically.
- Optic nerve gliomas. They are located around the optic nerves that connect the eyes to the brain.
- Oligodendrogliomas. They are tumors originating in the brain cells called oligodendrocytes, which are glial cells that make fatty substances to help nerve conduction in the brain.
- Embryonal tumors. These tumors, formerly called primitive neuroectodermal tumors (PNETs), develop in the early forms of nerve cells in the brain and spinal cord. Medulloblastomas are the most common embryonic tumors in children.
- Pineal tumors. They develop in the pineal gland of the brain. Pineoblastomas are the most common penial tumors, and germ cell tumors may also originate from the pineal gland.
- Craniopharyngiomas. They are benign, slow-growing brain tumors located near the pituitary gland.
- Mixed glial and neuronal tumors. These tumors are composed of both glial and neuronal cells components. Ganglioglioma and dysembryoplastic neuroepithelial tumors are examples of such tumors.
- Choroid plexus tumors. They are located in the choroid plexus. These tumors can be malignant (choroid plexus carcinomas) or benign (choroid plexus papillomas).
- Schwannomas. Schwannomas, also called neurilemmomas, are tumors originating from Schwan cells covering the nerves.
An absence of the recurrence of the disease after five years is considered a cure of brain tumors. However, regular follow-ups and screenings are needed to confirm it. Constant support and encouragement from parents and others around the child are essential for a child’s emotional well-being while fighting the tumor. Although the treatment is often extensive and long drawn out, children with brain tumors have better outcomes after treatment and rehabilitation therapies.
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- Surabhi Subramanian and Tahani Ahmad; Childhood Brain Tumors.
- Brain Tumors In Children.
- What is Ataxia?
- What Causes Brain and Spinal Cord Tumors In Children?
- Brain Tumors In Children.
- Risks and Complications.
- Pediatric Brain Tumors.
- Brain Tumors In Children.
- What Is The Expected Life Span Of Childhood Brain And Spinal Cord Cancer Tumors.
- Types of Brain and Spinal Cord Tumors In Children.