Meningiomas In Children: Diagnosis And Treatment

Overview

The nervous system is the most sensitive and important component of the human body, shielded by a number of defensive mechanisms. The meninges are membranes that cover the entire length of the brain along with the surrounding fluid. Meningiomas, which are tumours, harm the protective tissue layers surrounding the brain and spinal cord. The cerebrospinal fluid (CSF) moves between these layers.

Meningiomas are typically benign (not cancerous), but they can occasionally turn malignant (cancerous) if they spread to other parts of your body and infiltrate nearby tissues. Meningioma may be associated with diseases such as Neurofibromatosis (NF). Numerous symptoms may appear, including headaches, hearing loss, eye pressure, difficulty or problems with smelling, etc. The best treatment for meningioma needs a multidisciplinary team of doctors and surgeons.¹

Meningiomas in children

Children seldom develop a type of tumour called intracranial meningiomas. Unfortunately, this tumour tends to be more aggressive and atypical in children compared to adults, posing significant challenges for effective therapeutic interventions.

Epidemiology and incidence rates

According to histology, meningiomas account for 53.3% of benign central nervous system (CNS) tumours and 37.6% of primary CNS tumours. Meningiomas are more common as people age, with 66 years old being the median age of diagnosis. Meningiomas represent 1.7% of all CNS malignancies in patients aged 0 to 14 years. Females are more likely to develop benign and malignant meningiomas than males, with incidence ratios of 2:33 and 1:12, respectively. The incidence of meningioma is similar for both sexes in the age group 0-19. Children more often develop high-grade meningiomas, which are more likely to recur and have lower overall mortality rates.

Causes of meningiomas

Meningiomas are tumours that arise from the cells that make up the arachnoid membrane (arachnoid cap cells). Both meningioma and cancer share a common characteristic in that they always emerge from a clonal expansion originating from a single cell, as demonstrated by cytogenetic and array-comparative genomic hybridisation (array-CGH) investigations. This remains consistent even in cases where meningioma displays a benign pathophysiology, observed in 95% of cases.²

Similar to adult tumours, ionizing radiation may constitute an established environmental risk factor for pediatric meningiomas (accounting for 8% of all reported cases). This risk is particularly notable after radiation therapy for conditions such as medulloblastoma, ependymoma, glioma, or lymphoma. Additionally, families with germline mutations in genes like NF1, SMARCE1, BAP1, and SUFU have been associated with pediatric meningiomas.³ Clear-cell meningiomas can aid in diagnosing parents with a family history of meningiomas or meningiomatosis and identify germline loss-of-function mutations in the SMARCE1 gene.⁴

Risk factors

The development of the meningioma can be accelerated under certain conditions:

• Gender: Being a woman is considered a potential risk factor, as most meningioma patients are women
• Age: Being over the age of 60 is identified as a risk factor for meningioma development
• Ionizing radiation: Exposure to ionizing radiation is recognised as a risk factor that may accelerate the development of meningiomas⁵
• Hormone receptors: The majority of meningiomas have receptors for progesterone, estrogen, or both on the surface of their cells. Pregnant women, naturally producing high hormone levels, may experience more aggressive tumour growth. In addition, the risk of meningioma development appears to be higher in individuals undergoing hormone replacement therapy, where an artificial dosage of hormones is administered
• Neurofibromatosis type 2 (NF2): The rare hereditary condition of NF2 is known to accelerate the growth of benign tumours in the nervous system, including meningiomas
• Other potential risk factors: Meningioma may also be linked to other risk factors such as head trauma, chronic cell phone use, epilepsy, and smoking

Symptoms and clinical presentation

The signs and symptoms of meningioma vary based on the child's age, tumour size, and other factors. Although certain clinical indicators are more commonly observed in the pediatric population, the clinical presentation remains variable and ambiguous. Symptoms related to increased intracranial pressure, like headache, nausea, papilledema, and drowsiness may arise.

The presentation can also vary depending on the location of the tumour in the brain or spine. In many cases, signs and symptoms of meningioma develop gradually. Warning signs may include linguistic difficulties, seizures, memory loss, and migraines.

Diagnostic procedures

Medical history and physical examination

The diagnosis of meningioma involves several processes. Usually, the doctor may inquire about your past illnesses, radiation therapy treatments, and medical history. The doctor will also check your vision, hearing, balance, coordination, and reflexes. As a result, the area of your brain affected by the tumour can be identified based on the examination results.

Neuroimaging techniques 

Diagnosing meningioma relies on a thorough examination of the patient's medical history, a physical assessment, and radiological findings. The most effective diagnostic test for meningioma is brain magnetic resonance imaging (MRI) with contrast, highlighting the metabolic and chemical distinctions between the cancerous tumour and the surrounding healthy neural tissue. Serial imaging should be taken during the follow-up assessments, commonly through brain MRI.⁶

Two fundamental types of MRI are employed in meningioma diagnosis:

1. Functional MRI (fMRI): This type analyses the brain's architecture and detects changes in blood flow, providing valuable insights into the tumour's characteristics
2. Perfusion MRI: This variant allows visualisation of areas where blood flow to the brain may be reduced, aiding in the comprehensive diagnosis of meningiomas

For patients with implanted medical devices like pacemakers or cochlear implants, undergoing an MRI is not feasible due to potential magnetic interference. In such cases, computed tomography (CT) scans provide an alternative. By combining multiple X-rays, CT scans offer doctors an alternative means to observe and analyse structures within the brain.

Biopsy and histopathological analysis

In order to determine whether the tissue is malignant, the doctor takes cells from the tumour during a biopsy, which are then inspected under a microscope. This is a critical step in figuring out the tumour's grade.

Classification and grading of meningiomas

WHO classification system

Meningioma subtypes, which are 15 distinct meningioma variations recognised by the World Health Organization's (WHO) classification system, are classified into three categories based on three factors: growth rate, recurrence, and cellular characteristics.

Determining tumour grade and prognosis

Depending on their traits, meningiomas are classified into three categories. There are various subtypes of meningioma at each grade. Subtypes linked to geography and illness characteristics can be found via molecular testing.

• Grade I: Tumour grows slowly
• Grade II: Atypical, these meningiomas grow more quickly than grade I tumours and have a chance of recurrence after removal
• Grade III: Malignant or anaplastic, clear cell abnormalities, fastest at growing, and they can spread and infiltrate the brain

Treatment approaches

Although the first-line treatment is surgery, radiotherapy/radiosurgery is considered for atypical meningiomas.⁷

Multidisciplinary team and treatment planning

A multidisciplinary team of doctors, surgeons and physicians is required to treat meningioma. Before surgery, the treatment plan should be developed for each patient to reduce the possibility of unfavourable outcomes.⁸

Surgical intervention

The treatment goal for paediatric meningioma is the same as that in adults. Surgery remains the first-line treatment for this condition.⁹ The type of surgery performed depends on the size and location of the meningioma.

Craniotomy

Is a type of brain surgery where a surgeon opens your skull to access your brain. It's performed to treat tumours, epilepsy, and blood clots.

Endoscopic endonasal surgery

This approach doesn’t require opening the skull. It involves the use of an endoscope (a flexible tube with a video camera and light attached to it) to go through the nose to operate on areas at the front of the brain and the top of the spine.

Neuroendoscopic surgery

It is a minimally invasive surgery that involves using an endoscope to perform operations on the brain or spine.

Spinal surgery

Spine surgery is a procedure performed on your spinal column and surrounding tissue in case of a spinal meningioma. The surgeon makes an incision, usually in the back of the spine, where the tumour is often found. The surgeon carefully opens the meninges and removes the growth, avoiding the spinal cord and important nerves.

Complications and risks

Intracranial meningioma surgery always has a high risk of postoperative hematoma and infection because of the deep location of the skull base. Meningioma surgery has been linked to several reports of 30-day mortality.¹⁰

Radiation therapy

External beam radiation

Surgery often remains the main treatment of meningioma as it reduces the mass effect and confirms the diagnosis. However, radiation therapy has frequently been successful in the primary setting and is commonly used as adjuvant therapy for incompletely resected tumours.¹¹

Stereotactic radiosurgery

Stereotactic radiosurgery is employed for both primary and adjuvant treatment of benign meningiomas. It effectively addresses small- to medium-sized skull base meningiomas. This method has also demonstrated success in treating large meningiomas and superficial tumours. However, research indicates a decline in tumour control with increasing tumour size and for lesions closer to the surface. Moreover, radiation toxicity increases with tumour size. In situations where there is a high surgical risk for skull base meningiomas or when surgery is not a viable initial treatment for superficial meningiomas, exploring stereotactic radiosurgery is recommended.¹²

Chemotherapy

Chemotherapy is not frequently used to treat meningiomas. Chemotherapy may be suggested if a patient refuses surgery or if the tumour is too close to the spinal cord to be removed properly.

Emerging therapies and clinical trials

As a result of the molecular classification of meningioma, clinical trials may now be designed to allocate patients to relevant, targeted therapies based on the genetic subtypes of their tumours.¹³

Long-term monitoring and follow-up

Post-treatment surveillance

In order to provide patient-centred care during neuro-oncology survivorship, effective monitoring and treatment must involve coordination with primary care doctors and may require referral to other specialists and support services.¹⁴

Rehabilitation and supportive care

Patients usually acknowledge that they are unable to perform the same tasks as before. Assisting patients with rehabilitation and supportive care is crucial because it enables them to minimise the negative effects of their “new life”.¹⁵

Prognosis and outcomes

Factors influencing prognosis

Age, sex, degree of resection, previous irradiation, diagnosis of NF2, and presence of comorbidity are all potential prognostic factors.¹⁶

Survival rates and quality of life

Non-medical elements that affect the quality of life of people with brain tumours include psychological symptoms and social support. 

The effectiveness of diagnostic communication plays a crucial role in treatment adherence, subsequently influencing the overall quality of life. The development of disease-specific questionnaires and the implementation of long-term follow-up procedures could significantly enhance research related to individuals with brain tumours.¹⁷

Psychological and emotional support

Coping strategies for children and families

1. Small gestures of generosity, such as a smile, thank you, or a kind word, matter
2. Connecting with your loved ones, friends, coworkers, and neighbours and discussing concerns with them can help you see things from a fresh angle
3. Stay physically active, which is good for your physical health and mental well-being
4. Engage in continuous learning; acquiring new knowledge can boost your confidence and give you a sense of accomplishment
5. Be mindful;  being attentive to your thoughts, emotions, and surroundings allows for a better understanding of what is happening in the world

Support groups and counselling services

Support groups and counselling services often rely on a multitude of volunteers, many of whom are dedicated to a specific cause. Their commitments may involve bringing people together, raising awareness about an issue, spreading knowledge, or seeking financial support. Typically, there is also paid staff or administrative support involved.

Summary

• Meningiomas are typically benign (not cancerous) tumours, but they can occasionally turn malignant (cancerous) if they spread to other parts of your body and infiltrate nearby tissues
• Numerous symptoms may appear, including headaches, hearing loss, eye pressure, difficulty or problems with smelling
• Ionizing radiation exposure, hormone therapy, and neurofibromatosis type 2 are risk factors for meningioma
• Meningiomas can be diagnosed using either neuroimaging techniques like MRI or CT scan or biopsy and histopathological analysis
• Surgery is the main form of treatment for meningioma in adults and children. However, for atypical meningiomas, adjuvant radiotherapy or radiosurgery can be considered
• Children diagnosed with brain cancer in particular, need a lot of psychological and emotional assistance