Medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor in the pediatric population, accounting for approximately 20% of all childhood central nervous system malignancies. Clinically, MB often presents with symptoms related to increased intracranial pressure due to obstructive hydrocephalus, as well as cerebellar dysfunction. Histologically, it encompasses several variants, including classical, desmoplastic/nodular, extensive nodularity, and large cell/anaplastic types, each with distinct prognostic implications. Recent advances in molecular biology have revolutionized the classification of MB four main molecular subgroups: WNT, SHH, Group 3, and Group 4. These subgroups differ in their genetic alterations, cellular origins, clinical behavior, and outcomes. The WNT subgroup is associated with an excellent prognosis, while Group 3 tumors are typically more aggressive with poorer survival rates. Molecular stratification has enhanced risk assessment and guided more tailored therapeutic approaches. Standard treatment involves maximal safe surgical resection followed by craniospinal irradiation and chemotherapy, with adjustments based on age, molecular subtype, and risk stratification. Despite improved survival rates reaching 70–80% in recent decades, treatment-related long-term sequelae such as neurocognitive deficits, endocrine dysfunction, and secondary malignancies remain significant challenges. Ongoing research into the molecular underpinnings of MB continues to refine diagnostic accuracy, prognostic precision, and therapeutic strategies, offering hope for more effective and less toxic treatments in the future.