This research is being done to find out more information about a brain tumor called Embryonal Tumor with Multilayer Rosettes (ETMR) by collecting medical information from children who have this disease. The purpose of this research study is to create and maintain a research database for patients with ETMR. The database will include information about occurrence rates, patient information, tumor tissue information, and response to treatment. This will help advance our understanding of this rare disease. In addition, this study will include obtaining survival data and evaluating therapeutic response to expert consensus therapy, and procuring patient tumor tissue.