Undifferentiated Round Cell Sarcomas: A Comprehensive Review and Practical Diagnostic Guide with an Emphasis on Superficial Body Sites

-non-ETS fusion sarcomas. Despite these refinements, superficial presentations remain prone to misclassification. This review provides an overview of undifferentiated round cell sarcomas, emphasizing their clinical, histologic, immunohistochemical, and molecular features, while outlining important mimics at superficial sites. We highlight an integrated diagnostic framework that combines morphology, broad immunohistochemical panels, and molecular testing. Accurate recognition of these tumors is essential, as correct classification directly informs prognosis and therapeutic decision-making.