Guidance for the Diagnosis and Treatment of Rare Embryonal and Sarcomatous Brain Tumors-a Report from the Central Nervous System-International Registry for Rare Embryonal and Sarcomatous Tumors German Society of Pediatric Oncology and Hematology Study Group.

With the advent of multi-omic molecular profiling techniques, central nervous system tumor types previously not recognized by conventional neuropathological assessment have emerged, particularly among tumors formerly termed as "CNS- primitive neuroectodermal tumors." Given the diverse histopathological, molecular, radiological, and clinical characteristics of these tumors, diagnostic approaches and treatment strategies need to be adapted to our increasing knowledge. The small number of patients per year for individual tumor types precludes large cohort studies and mandates international cooperation and harmonization. To this end, the SIOPE Brain Tumor Group together with the European Reference Network for Pediatric Cancers has published the European Standards of Clinical Practice guidelines for rare embryonal and sarcomatous tumors.