Pediatric Medulloblastomas: Classification, Pathophysiology and Therapeutics
Medulloblastomas are a type of primary malignant brain tumour arising within the cerebellum and posterior cranial fossa adjacent to the fourth ventricle. Medulloblastomas are the most common primary malignant brain tumours in the pediatric population and an increasing body of basic and clinical research is providing important insights into the etiology, pathogenesis and development of novel therapeutics to treat these highly invasive tumours. Recent advances in genomics and transcriptomics have allowed researchers to classify and diagnose medulloblastomas based on differences in genetic and transcriptome factors. Based on these findings medulloblastomas have been classified into four main subgroups including the: 1) Wnt subgroup, 2) Shh subgroup, 3) Group 3 tumours and 4) Group 4 tumours. These advancements in classifying and diagnosing medulloblastomas are important as different tumour subgroups have different pathophysiology, differing prognoses and variable responses to treatment. This article will briefly highlight the latest classification criteria of pediatric medulloblastoma, review molecular and genetic features believed to be involved in the pathogenesis of each of the 4 subgroups of medulloblastoma and provide an overview of treatments and therapies that are currently available and in development for medulloblastoma.