Now Know Different Types of Glioma in Children

Glioma are a diverse group of brain and spinal cord tumors that arise from glial cells, which support and protect neurons in the central nervous system. In children, gliomas account for approximately half of all brain tumors, making them one of the most common types of pediatric brain cancers. Gliomas can vary significantly in their location, growth rate, and malignancy, and they are categorized based on the type of glial cells from which they originate.

This article explores the different types of glioma in children, their characteristics, symptoms, treatment options, and prognosis. Early detection and tailored treatment approaches are crucial to improving survival outcomes in pediatric glioma cases.

Also, read: Now Know Different Types of Brain and Spinal Cord Tumors in Children

What Are Gliomas?

Gliomas develop from glial cells in the brain or spinal cord. There are several types of glial cells, including astrocytes, oligodendrocytes, and ependymal cells, and each type can give rise to different forms of gliomas. Gliomas are classified by their cell of origin and their grade (degree of malignancy). The World Health Organization (WHO) grades gliomas on a scale from I (least malignant) to IV (most malignant). (Source)

Types of Gliomas in Children

1. Astrocytomas

• Definition: Astrocytomas are the most common type of glioma in children. They arise from astrocytes, star-shaped glial cells that provide structural support and regulate the blood-brain barrier.
• Pilocytic Astrocytoma (Grade I): The most common low-grade glioma in children. These tumors are typically slow-growing and localized, meaning they do not spread to other parts of the brain or spinal cord. They often form in the cerebellum, the part of the brain that controls movement and coordination.
• Diffuse Astrocytoma (Grade II): A slow-growing tumor that can infiltrate surrounding brain tissue, making complete surgical removal difficult. It most commonly affects the cerebral hemispheres.
• Anaplastic Astrocytoma (Grade III): A more aggressive, malignant tumor that tends to grow rapidly and spread into nearby brain tissue.
• Glioblastoma (Grade IV): The most aggressive and malignant type of astrocytoma, glioblastomas grow rapidly and are difficult to treat. They can occur in any part of the brain or spinal cord.
• Symptoms: Headaches, seizures, nausea, vomiting, and issues with movement, coordination, or vision.
• Treatment: Treatment for astrocytomas often includes surgery, especially for low-grade types like pilocytic astrocytoma. In higher-grade tumors, treatment may also involve radiation therapy and chemotherapy. (Source)

2. Brainstem Gliomas

• Definition: These tumors occur in the brainstem, the part of the brain that controls essential functions like breathing, heart rate, and blood pressure.
• Diffuse Intrinsic Pontine Glioma (DIPG): A highly aggressive tumor located in the pons region of the brainstem. DIPG is one of the most challenging pediatric brain tumors to treat due to its location and aggressive nature.
• Focal Brainstem Glioma: A less aggressive, more localized tumor, often easier to treat with surgery and radiation.
• Symptoms: Difficulty swallowing, problems with eye movement, facial weakness, balance issues, and limb weakness.
• Treatment: DIPG is typically treated with radiation therapy, though the prognosis is poor. Focal brainstem gliomas may be treated with surgery, chemotherapy, or radiation. (Source)

3. Ependymomas

• Definition: Ependymomas develop from ependymal cells, which line the ventricles of the brain and the central canal of the spinal cord. These tumors can occur in both the brain and the spinal cord.
• Characteristics: Ependymomas are classified into three types: subependymoma (Grade I), classic ependymoma (Grade II), and anaplastic ependymoma (Grade III). They may block the flow of cerebrospinal fluid, leading to hydrocephalus (fluid buildup in the brain).
• Symptoms: Headaches, nausea, vomiting, balance problems, and hydrocephalus-related symptoms such as drowsiness or irritability.
• Treatment: Surgery is often the first line of treatment for ependymomas, followed by radiation therapy. Chemotherapy may be used in some cases, particularly for younger children. (Source)

4. Oligodendrogliomas

• Definition: Oligodendrogliomas arise from oligodendrocytes, which produce the myelin sheath that protects nerve cells.
• Characteristics: Oligodendrogliomas are rare in children, accounting for about 5% of pediatric gliomas. These tumors tend to grow slowly and can be found in the cerebral hemispheres.
• Symptoms: Seizures, headaches, and neurological deficits such as weakness or difficulty with speech and coordination.
• Treatment: Surgery to remove the tumor, followed by radiation therapy and, in some cases, chemotherapy. Due to the tumor’s infiltrative nature, complete removal is often difficult. (Source)

5. Mixed Gliomas

• Definition: Mixed gliomas, also known as oligoastrocytomas, contain both oligodendrocytes and astrocytes. These tumors are uncommon in children but may present with a combination of symptoms associated with both cell types.
• Characteristics: Mixed gliomas vary in their growth rate and malignancy, depending on the proportion of astrocytic and oligodendroglial cells.
• Symptoms: Headaches, seizures, and neurological impairments such as difficulty with movement or speech.
• Treatment: Surgery, radiation, and chemotherapy, depending on the grade and location of the tumor. (Source)

Symptoms of Glioma in Children

The symptoms of pediatric gliomas depend on the location, size, and grade of the tumor. Common symptoms include:

• Headaches (often worse in the morning)
• Nausea and vomiting
• Seizures
• Vision problems (blurry vision, double vision)
• Weakness in limbs
• Difficulty walking or maintaining balance
• Changes in personality or behavior
• Fatigue and drowsiness

Children with gliomas may also experience more specific symptoms related to the part of the brain or spinal cord affected by the tumor. For example, tumors in the brainstem can lead to problems with swallowing, breathing, and facial movement, while tumors in the cerebellum can cause coordination and movement issues. (Source)

Diagnostic Procedures for Gliomas

Diagnosing gliomas in children involves a range of tests and imaging studies to determine the location, type, and grade of the tumor:

• Magnetic Resonance Imaging (MRI): The most common imaging technique used to diagnose gliomas, MRI provides detailed images of the brain and spinal cord.
• Biopsy: A small sample of the tumor is taken during surgery to examine under a microscope and confirm the type and grade.
• Computed Tomography (CT) Scan: Sometimes used to complement MRI, particularly if bone involvement needs to be evaluated.
• Lumbar Puncture: This test checks for cancer cells in the cerebrospinal fluid, especially in cases of high-grade gliomas that may spread through the fluid. (Source)

Treatment Options for Pediatric Gliomas

1. Surgery: Surgery is often the first step in treating gliomas, especially for low-grade tumors. Complete removal of the tumor may be possible in some cases, while in others, only partial removal is achievable due to the tumor’s location near critical brain structures.
2. Radiation Therapy: Radiation is commonly used after surgery to kill any remaining cancer cells, particularly in high-grade gliomas. It is also a primary treatment for tumors like DIPG, which cannot be surgically removed.
3. Chemotherapy: Chemotherapy is used to treat high-grade gliomas, especially in younger children where radiation may pose significant long-term risks. It can also be used in conjunction with surgery and radiation for more aggressive tumors.
4. Targeted Therapies: Newer treatment options such as targeted therapies are being explored for specific genetic mutations found in certain gliomas, providing a more personalized treatment approach.
5. Clinical Trials: Children with aggressive or recurrent gliomas may be eligible for clinical trials that offer experimental treatments, such as immunotherapy or gene therapy. (Source)

Prognosis and Survival Rates

The prognosis for children with gliomas depends on several factors, including the tumor type, grade, and location.

• Low-Grade Gliomas: Children with low-grade gliomas, such as pilocytic astrocytomas, have a favorable prognosis, with long-term survival rates exceeding 90% in some cases.
• High-Grade Gliomas: High-grade gliomas like glioblastomas and anaplastic astrocytomas have a poorer prognosis, with lower survival rates due to their aggressive nature.
• Brainstem Gliomas: Diffuse intrinsic pontine glioma (DIPG) remains one of the most difficult pediatric brain tumors to treat, with a median survival of less than a year. (Source)

Also, read: Now Know All About Cancer Screening Tests

Conclusion

Gliomas in children encompass a wide range of tumor types, each with unique characteristics, symptoms, and treatment challenges. Early detection, coupled with advances in surgical techniques, radiation therapy, and chemotherapy, has improved the prognosis for many pediatric glioma patients. However, ongoing research and clinical trials are essential to finding more effective treatments for aggressive gliomas like DIPG. Parents and caregivers should work closely with a multidisciplinary medical team to develop a personalized treatment plan for their child.