Developmental Origins of Aggressive Medulloblastoma

Medulloblastomas represent a heterogeneous group of cerebellar tumors that constitute the most frequent primary pediatric solid malignancy. Molecular characterization of these tumors have led to the understanding that distinct subtypes possess characteristic properties such as gene expression profile, histological classification, and degree of dissemination that are predictive of disease progression and prognosis. Fractionation of primary medulloblastomas has led to the appreciation of brain tumor stem cells (BTSC) that may be driving the more aggressive and malignant disease. However, the developmental origins of these cells as well as the influences of early mutations in tumor suppressors on development and tumorigenesis remain unclear.