title: 29F
design: A retrospective chart review was performed of all patients treated at Childrens Cancer Hospital Egypt diagnosed with a pineal region tumor between June 2013 and March 2021 for whom a research blood sample was available. Plasma samples were profiled for miRNA expression and DESeq2 was used to compare between pure germinoma and other tumor types. Differentially expressed miRNAs were identified. The area under the curve of the receiver operating characteristic curve was constructed to evaluate diagnostic performance.