CIC-Rearranged Sarcomas With Unusual Morphology and Molecular Features: A Case Series of Pediatric Patients

CIC-rearranged sarcomas represent a rare and aggressive category of undifferentiated small round cell sarcomas with distinct clinicopathological and molecular features. This study presents a case series of four pediatric CIC-rearranged sarcomas, including an index case with unusual chondroid and osseous metaplasia and three additional cases demonstrating the clinicopathological spectrum of these tumors. We present four pediatric CIC-rearranged sarcomas, all with CIC::DUX4 fusions confirmed by next-generation sequencing. This series expands the morphological and molecular spectrum of these tumors, underscoring their heterogeneity and the necessity of molecular profiling for diagnosis.