Medulloblastoma Guide: Complete Care & Hope

What is Medulloblastoma?

Medulloblastoma is one of the  most common malignant brain tumors in childhood, often affecting the cerebellar region of the brain. Tumors in this area can impact a child's balance, coordination, and cognitive abilities. Some grow rapidly and show early signs, while others progress silently and are diagnosed in advanced stages. Early detection and a multidisciplinary treatment approach are key to improving both survival rates and long-term quality of life.

Medulloblastoma  is an aggressive brain tumor that originates near the cerebellum, the part of the brain responsible for balance and coordination. It is most commonly diagnosed in children between the ages of 5 and 9, with a higher incidence in boys. Classified as a malignant pediatric brain tumor, medulloblastoma has a high rate of cell division and may spread (metastasize) to other parts of the central nervous system, including the spinal cord.

Due to its aggressive nature, medulloblastoma requires urgent diagnosis and a coordinated, multidisciplinary treatment plan. It is considered a central focus within pediatric neuro-oncology due to its prevalence and potential impact on development.

Causes and Risk Factors of Medulloblastoma

While the precise cause of medulloblastoma remains unclear, research indicates that both genetic mutations and environmental factors may play a role in its development.

Key  medulloblastoma risk factors  include:

• Genetic syndromes such as Gorlin syndrome or Turcot syndrome are linked to an increased risk of developing brain tumors.
• Family history: While most cases are sporadic (not inherited), children who have a family history of brain tumors may have a slightly higher risk of developing one themselves.
• Exposure to radiation is another environmental factor that may increase the risk of developing tumors.
• The tumor affects both boys and girls, but it is observed more frequently in male children.
• Medulloblastoma represents more than 20% of pediatric brain tumors, making it the most common malignant brain tumor in children.

Symptoms of Medulloblastoma

Medulloblastoma symptoms often arise from increased intracranial pressure and compression of the cerebellum and nearby brain structures. The specific symptoms may vary based on the child's age and the size of the tumor, but common signs include:

Early Warning Signs

• Severe headaches, especially in the morning, are a common early symptom.
• Nausea and vomiting, often linked to increased intracranial pressure.
• Behavioral changes such as irritability, decreased motivation, or difficulties concentrating at school may be subtle but important early warning signs.

Advanced Symptoms of Medulloblastoma

As medulloblastoma advances, it can lead to more pronounced and severe neurological impairments. These symptoms occur as the tumor exerts pressure on the cerebellum and surrounding brain structures.

Common Advanced Symptoms Include:

• Balance difficulties and unsteady walking, resulting from the tumor compressing the cerebellum.
• Double vision, loss of visual field, or involuntary eye movements (nystagmus).
• Speech difficulties, often due to disruption of cerebellar pathways.

Symptoms in Infants and Young Children

• Medulloblastoma may appear differently in babies and toddlers, who cannot communicate their symptoms verbally. Look for warning signs such as:
• Rapid head growth, bulging fontanelles (soft spots), irritability, and persistent crying.
• Changes in muscle tone”such as decreased tone (hypotonia) or increased tone (spasticity)”can occur alongside developmental delays.

Hydrocephalus and Associated Symptoms

• When a tumor is located near the fourth ventricle, it can block the flow of cerebrospinal fluid, resulting in hydrocephalus (a buildup of fluid in the brain).
• Common hydrocephalus-related symptoms include:
• Headaches, blurred vision, confusion, and lethargy.
• This condition may require emergency neurosurgical intervention to relieve the pressure.

Diagnostic Methods for Medulloblastoma

Accurate diagnosis is essential for starting the appropriate treatment plan. Diagnosing medulloblastoma requires a combination of thorough clinical evaluation and advanced imaging techniques.

Steps in Diagnosing Medulloblastoma:

• A comprehensive neurological examination is performed first. This involves assessing eye movements, muscle strength, balance, and reflexes to help identify which regions of the brain may be affected.
• MRI (Magnetic Resonance Imaging) is considered the gold standard for diagnosing brain tumors. It provides detailed information about the tumor's location, size, and its relationship to surrounding structures.

Biopsy:

• Tissue samples collected during or before surgery are examined under a microscope to confirm the type and characteristics of the tumor cells.
• In some cases, a lumbar puncture (spinal tap) may be performed to determine whether the cancer has spread to the cerebrospinal fluid (CSF).
• Molecular profiling can also be performed to examine the genetic features of the tumor and design a personalized, targeted treatment plan.

Medulloblastoma Classification and Subtypes

Modern classification of medulloblastoma is based on both genetic and histological features of the tumor. Identifying the specific subtype is crucial for predicting prognosis and customizing treatment plans.

Molecular Subtypes of Medulloblastoma:

• WNT subtype: Associated with the best prognosis, typically diagnosed in children over age 5.
• SHH (Sonic Hedgehog) subtype: This subtype is commonly seen in infants and young adults. Certain subgroups within the SHH subtype may exhibit resistance to chemotherapy.
• Group 3: The most aggressive form, with a high likelihood of metastasis.
• Group 4: More frequently affects male children and is associated with an intermediate prognosis.

Identifying these subtypes is essential for developing effective treatment strategies and for predicting long-term survival outcomes.

Medulloblastoma Treatment Options

Treating medulloblastoma requires a multidisciplinary approach that includes surgery, radiation therapy, and chemotherapy. The primary objective is to completely remove the tumor, prevent its recurrence, and preserve neurological function as much as possible.

Standard Medulloblastoma Treatment Protocol:

• Once the diagnosis is confirmed, a neurosurgical team typically coordinates the treatment process.
• Surgical removal of the tumor is typically the first step in treatment. The goal is to excise as much of the tumor mass as possible. However, complete removal may not always be feasible if the tumor is located near critical structures in the brain.
• Radiotherapy is typically started within the first few weeks after surgery. The treatment is meticulously planned to target both the brain and the spinal cord, taking into account the risk of tumor cells spreading to these areas.
• Chemotherapy is given either at the same time as radiotherapy or after it. Common drugs used include vincristine, cisplatin, and cyclophosphamide. These medications help eliminate any remaining microscopic cancer cells after surgery.

Medulloblastoma Treatment in Children

Treatment strategies for pediatric medulloblastoma are tailored based on the child's age and the tumor's molecular subtype.

• For children under age 3, it is crucial to delay or minimize radiation exposure to protect healthy brain development.
• In very young patients, intensified chemotherapy protocols may be used to delay or potentially avoid the need for radiotherapy.
• A team of specialists”including pediatric oncologists, pediatric neurosurgeons, neuropsychologists, physiotherapists, and dietitians”collaborates to ensure both successful cancer treatment and healthy developmental progress.
• This collaborative approach greatly improves treatment outcomes and significantly enhances the child's long-term quality of life.

Post-Treatment Follow-Up and Long-Term Care

Recovery after medulloblastoma treatment involves not only ongoing monitoring for cancer recurrence, but also careful attention to the child's physical, cognitive, and emotional development.

Key Elements of Post-Treatment Management:

• After treatment, regular MRI scans are scheduled to monitor for recurrence: every three months during the first year, and every six months during the second year.
• Children's academic performance, social integration, and psychological well-being are closely tracked throughout their recovery.
• The first two years after treatment are especially important because the risk of recurrence is highest during this period.
• Late effects such as hearing loss, growth retardation, and hormonal imbalances may develop after treatment. Therefore, long-term care requires coordinated follow-up with pediatricians, endocrinologists, and child psychiatrists.

Most of these side effects can be managed with supportive care and usually improve over time.

*  Liv Hospital Editorial Board  has contributed to the publication of this content .
* The contents of this page are for informational purposes only. Please consult your doctor for diagnosis and treatment. This page does not provide information on medical healthcare services at Liv Hospital.

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