Subsets of primitive round-cell sarcomas remain difficult to diagnose and classify. Among
these is a rare round-cell sarcoma that harbors a CIC gene rearrangement known as CIC-
rearranged undifferentiated round-cell sarcoma, which is most commonly fused to the DUX4
gene. Owing to its aggressive clinical behavior and potential therapeutic implications,
accurate identification of this novel soft tissue sarcoma is necessary. Definitive diagnosis
requires molecular confirmation, but only a few centers are as yet able to perform this test …