First Reported Saudi Cases of Intracranial Myxoid Mesenchymal Tumors with EWSR1-CREB Fusions: Diagnostic and Therapeutic Dilemmas

Abstract Intracranial myxoid mesenchymal tumors (IMMTs) are rare tumors with distinct histological and genetic features. Recently, identified as a new distinct entity in the WHO 2021 CNS tumor classification, they pose diagnostic and therapeutic challenges because of their rarity and overlap with other CNS tumors. Herein, we present the first two cases in Saudi Arabia in both pediatric and adult populations. The aim of our study was to analyze clinical radiological and histological features. We also included the molecular findings of our cases and reviewed the literature concerning previously reported cases. Our two patients were diagnosed at King Fahad Specialist Hospital, Dammam, Saudi Arabia. We collected all the relevant clinical data, imaging studies, and histopathological reports and evaluated their treatment outcomes. The molecular test was performed via next-generation sequencing (NGS), confirming the presence of the EWSR1-CREB fusion mutation. We concluded that there are two different variants of this disease with specific clinical histopathological and molecular characteristics. We believe that this report makes a valuable contribution to the scientific literature on intracranial myxoid mesenchymal tumors (IMMTs), particularly in the context of the Middle East, which will further refine the diagnostic skill of pathologists and aid in planning therapeutic strategies.