Congenital Undifferentiated Retroperitoneal Sarcoma With YWHAE::NUTM2B Fusion From the Abdomen to the Brain

YWHAE::NUTM2B fusion-positive undifferentiated sarcomas in infants have been recently described as molecular characterization increases to classify challenging solid tumor cases. The impact of this molecular distinction on clinical behavior remains unclear, posing significant challenges for treatment decision-making.

Data were obtained from the patient's medical record, including the diagnostic workup and management. A review of previously published cases was performed..

We present a case of congenital undifferentiated retroperitoneal sarcoma harboring a YWHAE::NUTM2B fusion, highlighting the potential significance of brain imaging surveillance in disease management.

This case, combined with others, reveals a potential pattern of central nervous system (CNS) metastasis within this molecular subgroup, thus highlighting the importance of brain surveillance imaging and the relevance of CNS-penetrant chemotherapy-based regimens.