PATH-39. A 44-YEAR-OLD FEMALE WITH DICER1-MUTANT PRIMARY INTRACRANIAL SARCOMA WITH IMAGING NEAR END OF LIFE

Abstract DICER1-mutant intracranial sarcomas were recently defined by WHO in the 2021 CNS tumor classifications. Currently there is a lack of literature describing clinical nature this disease. Here we present case primary sarcoma with DICER1 mutation and unknown etiology. A 44-year-old female presented aphasia right-sided weakness. Clinical imaging confirmed presence hemorrhagic mass left frontal lobe superior falx. The patient underwent two surgical resections, but clear diagnosis was difficult to make due heterogenous histological features inconclusive genomic testing. samples sent National Institute Health where genetic testing indicated E1813D high allele frequency (97%), TP53 (95%), variant NF1 splice site (96%). This resulted sarcoma. treated temozolomide, bevacizumab, CPT-11. 382 days after originally identified, died. detailed analysis radiographic images performed creating T1-weighted post-contrast enhancement maps (T1C) T2-weighted fluid attenuated inversion recovery (FLAIR) hyper-intensity for each timepoint. We plotted these volumes over time alongside patient’s treatment history. Large spikes T1C FLAIR volume seen 4 prior initiation temozolomide 31 CPT-11 ended. At final MRI, both about times greater than that initial scan. Despite disease’s aggressive nature, it can be accurately diagnose, part very few studies investigating rare tumor. With addition CNS5, future should examine behavior tumors, aiding earlier improvement guidance.