Medulloblastoma.

Medulloblastoma is the most common malignant brain tumor in children. Patients with medulloblastoma are stratified into ''standard'' and ''high'' risk categories based on age at diagnosis, degree of surgical resection, and disease spread. In children older than 3 years of age, the long-term survival can be achieved in approximately 85% of standard risk patients and 70% of high risk patients with a combination of chemotherapy and irradiation. Younger children, particularly infants, are at a significantly higher risk of side-effects of treatment. Despite tremendous progress in the field of molecular biology of medulloblastoma, much remains to be achieved in understanding the pathogenesis, critical pathways responsible for medulloblastoma, and molecular risk stratification, and in devising treatment strategies with even better survival and less long-term sequelae.